[release/6.0.1xx-preview7] Update dependencies from dotnet/installer

[dotnet-maestro]

This pull request updates the following dependencies

Coherency Updates

The following updates ensure that dependencies with a CoherentParentDependency
attribute were produced in a build used as input to the parent dependency's build.
See Dependency Description Format

• Coherency Updates:
  • Microsoft.NET.ILLink.Tasks: from 6.0.100-preview.6.21322.1 to 6.0.100-preview.6.21365.1 (parent: Microsoft.Dotnet.Sdk.Internal)
  • Microsoft.NETCore.App.Ref: from 6.0.0-preview.7.21326.8 to 6.0.0-preview.7.21369.8 (parent: Microsoft.Dotnet.Sdk.Internal)

From https://github.com/dotnet/installer

• Subscription: 95703ce6-24e6-46ee-08a4-08d948adff43
• Build: 20210719.21
• Date Produced: 7/20/2021 6:59 AM
• Commit: d553cd737ef78d11cbf56cd4ef273ce3026ee14e
• Branch: refs/heads/release/6.0.1xx-preview7

• Updates:
  • Microsoft.Dotnet.Sdk.Internal: from 6.0.100-preview.7.21327.2 to 6.0.100-preview.7.21369.21
  • Microsoft.NET.ILLink.Tasks: from 6.0.100-preview.6.21322.1 to 6.0.100-preview.6.21365.1
  • Microsoft.NETCore.App.Ref: from 6.0.0-preview.7.21326.8 to 6.0.0-preview.7.21369.8

[jonathanpeppers]

I'm thinking this will be green now.

[jonpryor]

Commit message:

Bump to dotnet/installer/release/6.0.1xx-preview7@808795cc 6.0.100-preview.7.21369.5 (#6097)

Fixes: https://github.com/xamarin/java.interop/issues/854

Changes: https://github.com/dotnet/installer/compare/e8b3b6bea1e37086869ba9aeafe65caa298537e7...808795cca8cfaa143ef556cac0dc40d15d2dc186

    % git diff --shortstat e8b3b6be...808795cc
     102 files changed, 2218 insertions(+), 2674 deletions(-)

Changes: https://github.com/mono/linker/compare/a07cab7b71a1321a9e68571c0b6095144a177b4e...9ecf5bd2809f93d98c1dbea640790ca5a88d35ec

    % git diff --shortstat a07cab7b...9ecf5bd2
     81 files changed, 2122 insertions(+), 246 deletions(-)


Changes: https://github.com/dotnet/runtime/compare/02f70d0b903422282cd7ba8037de6b66ea0b7a2d...8d3afa3a4a42021be024ffa4a1dee77e35d33911

    % git diff --shortstat 02f70d0b...8d3afa3a
     2518 files changed, 122843 insertions(+), 33676 deletions(-)

Changes: https://github.com/xamarin/java.interop/compare/a5ed8919fb2ec894cb8144e51ae7c29b4811ee2a...4fb7c147f8c6eb9bf94d9bfb8305c7d2a7a9fb33

  * xamarin/java.interop@4fb7c147: [build] set $(DisableImplicitNamespaceImports) by default (#859)
  * xamarin/java.interop@855ecfa3: [generator] Don't generate unexpected NRT types like `void?` (#856)
  * xamarin/java.interop@4a02bc32: Revert "[Xamarin.Android.Tools.Bytecode] hide nested types (#827)" (#855)
  * xamarin/java.interop@95c9b79d: [generator] Avoid 'error (…):' construct in diagnostic messages (#851)
  * xamarin/java.interop@7c4f7db0: [build] Bump to Mono with MSBuild 16.10 (#848)
  * xamarin/java.interop@0227cdae: [generator] Gracefully handle BindingGeneratorException. (#845)
  * xamarin/java.interop@ce1750fd: Add SECURITY.md (#846)

Context: https://github.com/dotnet/runtime/pull/55384
Context: https://github.com/dotnet/sdk/pull/18639

Updates:

  * Microsoft.Dotnet.Sdk.Internal: from 6.0.100-preview.7.21327.2 to 6.0.100-preview.7.21369.5
  * Microsoft.NET.ILLink.Tasks: from 6.0.100-preview.6.21322.1 to 6.0.100-preview.6.21365.1
  * Microsoft.NETCore.App.Ref: from 6.0.0-preview.7.21326.8 to 6.0.0-preview.7.21368.2

dotnet/runtime#55384 broke how .NET 6 interacts with
`AndroidClientHandler`.  Fix this by introducing a new
`Xamarin.Android.Net.AndroidMessageHandler` type for use on .NET 6,
and update the .NET 6 `AndroidClientHandler` to delegate to
`AndroidMessageHandler`.

`AndroidMessageHandler` doesn't exist on Legacy.

Update `.apkdesc` files:

  * `BuildReleaseArm64SimpleDotNet` is ~37KB smaller
  * `BuildReleaseArm64XFormsDotNet` is ~62KB larger.

Update `tests/api-compatibility/api-compat-exclude-attributes.txt`
so that `T:System.Runtime.CompilerServices.CompilerGeneratedAttribute`
is ignored.  `[CompilerGeneratedAttribute]` is emitted as part of
C# 3 "auto-props":

	public T Property { get; set; }

Converting this into a "real" property:

	T value;
	public T Property {
	    get => value;
	    set => this.value = value;
	}

results in the `_CheckApiCompatibility` target complaining about an
API break.  We don't care; ignore `[CompilerGeneratedAttribute]`.

Remove `$(SelfContained)` property: early on in .NET 5 (yes 5)
development, the Xamarin.Android SDK needed to specify
`$(SelfContained)` by default in order to produce `.apk` files.

After we became a proper workload, setting the value became
unnecessary.  It also didn't actually do anything because
dotnet/sdk overwrote the value.

Starting in dotnet/sdk#18639,
`Microsoft.NET.RuntimeIdentifierInference.targets` is now being
imported *after* a workload, which meant that dotnet/sdk no longer
overwrote our `$(SelfContained)` value, which broke things:

	error NETSDK1031: It is not supported to build or publish a self-contained application without specifying a RuntimeIdentifier. You must either specify a RuntimeIdentifier or set SelfContained to false.

We can simply remove `$(SelfContained)` now, and rely on
dotnet/sdk to set this value.

Co-authored-by: Jonathan Peppers <jonathan.peppers@microsoft.com>
Co-authored-by: Steve Pfister <steve.pfister@microsoft.com>