[github] Use ".NET Android", not "Android for .NET" (dotnet#7882)

Our current terminology is to use ".NET Android", not
"Android for .NET".

Additionally, update the `$(TargetFramework)` example from
`net6.0-android` to `net7.0-android`.

Update our GitHub templates accordingly.

Co-authored-by: Jonathan Pobst <[email protected]>

Author: jonpryor

.github/ISSUE_TEMPLATE/01-building-an-application.yml

@@ -15,7 +15,7 @@ body:
       multiple: true
       options:
       - Classic Xamarin.Android (MonoAndroid12.0, etc.)
-      - Android for .NET (net6.0-android, etc.)
+      - .NET Android (net7.0-android, etc.)
     validations:
       required: true
   - type: input

.github/ISSUE_TEMPLATE/02-running-an-application.yml

@@ -15,7 +15,7 @@ body:
       multiple: true
       options:
       - Classic Xamarin.Android (MonoAndroid12.0, etc.)
-      - Android for .NET (net6.0-android, etc.)
+      - .NET Android (net7.0-android, etc.)
     validations:
       required: true
   - type: input

.github/ISSUE_TEMPLATE/03-mono-android-api.yml

@@ -20,7 +20,7 @@ body:
       multiple: true
       options:
       - Classic Xamarin.Android (MonoAndroid12.0, etc.)
-      - Android for .NET (net6.0-android, etc.)
+      - .NET Android (net7.0-android, etc.)
     validations:
       required: true
   - type: input

.github/ISSUE_TEMPLATE/04-binding-a-java-library.yml

@@ -17,7 +17,7 @@ body:
       multiple: true
       options:
       - Classic Xamarin.Android (MonoAndroid12.0, etc.)
-      - Android for .NET (net6.0-android, etc.)
+      - .NET Android (net7.0-android, etc.)
     validations:
       required: true
   - type: input

.github/ISSUE_TEMPLATE/05-other.yml

@@ -15,7 +15,7 @@ body:
       multiple: true
       options:
       - Classic Xamarin.Android (MonoAndroid12.0, etc.)
-      - Android for .NET (net6.0-android, etc.)
+      - .NET Android (net7.0-android, etc.)
     validations:
       required: true
   - type: input