Quota API GA version SDK updates. (#17965)

* Updates for GA version -
<AzureApiTag>Capacity_2020-10-01-preview;Capacity_2020-10-25;</AzureApiTag>

* Updating release notes.

* Updating version to -Preview - 1.15.0-preview

* Updated Package release notes.

* Removing -Preview from changelog.md to fix CI build error.

* Adding -Preview to Package version.

* Updating recorded Tests.

* Updating Tests.

* Uprating the version to - <Version>1.15.0-preview</Version> in csproj file.

* Updating Tests.

* Updating commit ID.

* Removing model files not nrequired.

Author: rahuls-microsoft

eng/mgmt/mgmtmetadata/reservations_resource-manager.txt

@@ -4,11 +4,11 @@ Commencing code generation
 Generating CSharp code
 Executing AutoRest command
 cmd.exe /c autorest.cmd https://github.com/Azure/azure-rest-api-specs/blob/master/specification/reservations/resource-manager/readme.md --csharp --version=latest --reflect-api-versions --csharp-sdks-folder=D:\azure-sdk-for-net\sdk
-2019-10-28 03:49:20 UTC
+2020-12-02 11:46:23 UTC
 Azure-rest-api-specs repository information
 GitHub fork: Azure
 Branch:      master
-Commit:      08800e55784acd375627f6f2f3ecaddbbbc41c3c
+Commit:      f384a496b53871adf27fb4101c605f6aa777a499
 AutoRest information
 Requested version: latest
 Bootstrapper version:    autorest@2.0.4283

sdk/reservations/Microsoft.Azure.Management.Reservations/AzSdk.RP.props

@@ -1,7 +1,7 @@
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <!--This file and it's contents are updated at build time moving or editing might result in build failure. Take due deligence while editing this file-->
   <PropertyGroup>
-    <AzureApiTag>Capacity_2019-07-19-preview;Capacity_2019-04-01;</AzureApiTag>
+    <AzureApiTag>Capacity_2020-10-01-preview;Capacity_2020-10-25;</AzureApiTag>
     <PackageTags>$(PackageTags);$(CommonTags);$(AzureApiTag);</PackageTags>
   </PropertyGroup>
 </Project>

sdk/reservations/Microsoft.Azure.Management.Reservations/CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Microsoft.Azure.Management.Reservations release notes
 
+### Changes in 1.15.0-preview
+**Notes**
+
+* Add quota GA APIs.
+* Removed AutoQuotaIncrease APIs from GA version. It's available in preview version -1.14.0-preview.
+
 ### Changes in 1.14.0-preview
 **Notes**