Set java 11 as expected java version in all templates (#160349)

Bump templates from java 8 to java 11.

fixes flutter/flutter#156111 

I want to talk to @gmackall before merging to talk through the
consequences.


## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Gray Mackall <34871572+gmackall@users.noreply.github.com>

Author: reidbaker

packages/flutter_tools/templates/app/android-java.tmpl/app/build.gradle.kts.tmpl

@@ -11,12 +11,12 @@ android {
     ndkVersion = flutter.ndkVersion
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8.toString()
+        jvmTarget = JavaVersion.VERSION_11.toString()
     }
 
     defaultConfig {

packages/flutter_tools/templates/app/android-kotlin.tmpl/app/build.gradle.kts.tmpl

@@ -11,12 +11,12 @@ android {
     ndkVersion = flutter.ndkVersion
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8.toString()
+        jvmTarget = JavaVersion.VERSION_11.toString()
     }
 
     defaultConfig {

packages/flutter_tools/templates/module/android/deferred_component/build.gradle.tmpl

@@ -23,8 +23,8 @@ android {
     compileSdk = flutter.compileSdkVersion
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     sourceSets {

packages/flutter_tools/templates/module/android/host_app_common/app.tmpl/build.gradle.tmpl

@@ -7,8 +7,8 @@ android {
     compileSdk = {{compileSdkVersion}}
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     defaultConfig {

packages/flutter_tools/templates/module/android/library_new_embedding/Flutter.tmpl/build.gradle.tmpl

@@ -32,8 +32,8 @@ android {
     ndkVersion = flutter.ndkVersion
 
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
     }
 
     defaultConfig {