Bump $(AndroidNetPreviousVersion) to 34.0.79 (#8693)

Context: fd47b02761
Context: https://dotnet.microsoft.com/platform/support/policy/maui

Changes: d12da3a1...87e4a6d8

  * xamarin/xamarin-android@87e4a6d89: [release/8.0.1xx] localization changes for `XA1039` (xamarin/xamarin-android#8674)
  * xamarin/xamarin-android@f61c76030: [workload] Allow installation on linux-arm64 (xamarin/xamarin-android#8500)
  * xamarin/xamarin-android@4cdf1e018: [Xamarin.Android.build.Tasks] `<CheckDuplicateJavaLibraries/>` ignores `repackaged.jar` (xamarin/xamarin-android#8664)
  * xamarin/xamarin-android@77ac82a11: [release/8.0.1xx] [Xamarin.Android.Build.Tasks] XA1039 warning for Android.Support (xamarin/xamarin-android#8648)
  * xamarin/xamarin-android@c22c17fbe: [Xamarin.Android.Build.Tasks] fix warning when missing `proguard-android.txt` (xamarin/xamarin-android#8641)
  * xamarin/xamarin-android@31f031a67: Localized file check-in by OneLocBuild Task (xamarin/xamarin-android#8643)
  * xamarin/xamarin-android@3da479192: LEGO: Merge pull request 8642
  * xamarin/xamarin-android@dbf100d49: Update a number of l18n files (xamarin/xamarin-android#8633)
  * xamarin/xamarin-android@d2da5bf4e: Bump com.android.tools:r8 from 8.1.72 to 8.2.33 (xamarin/xamarin-android#8577)
  * xamarin/xamarin-android@9f9114afc: Bump com.android.tools:r8 from 8.1.56 to 8.1.72 (xamarin/xamarin-android#8532)
  * xamarin/xamarin-android@666777248: Fix ServerCertificateCustomValidator on API 21-23 (xamarin/xamarin-android#8637)
  * xamarin/xamarin-android@940f059b8: [Mono.Android] Fix ServerCertificateCustomValidator (xamarin/xamarin-android#8594)
  * xamarin/xamarin-android@351bfa3f0: Bump to dotnet/runtime/release/8.0@a6e4834d53 8.0.1 (xamarin/xamarin-android#8616)
  * xamarin/xamarin-android@64363367d: [Microsoft.Android.Templates] New files should open editor (xamarin/xamarin-android#8623)
  * xamarin/xamarin-android@26752564d: Bump to dotnet/installer@461c776642 8.0.101-servicing.23614.6
  * xamarin/xamarin-android@6972027f0: Localized file check-in by OneLocBuild Task (xamarin/xamarin-android#8589)
  * xamarin/xamarin-android@73efcfcad: [Xamarin.Android.Buid.Tasks] don't set $(PublishSelfContained) for .NET 9 (xamarin/xamarin-android#8565)
  * xamarin/xamarin-android@3333306b8: LEGO: Merge pull request 8587
  * xamarin/xamarin-android@38e950b41: Localized file check-in by OneLocBuild Task (xamarin/xamarin-android#8576)
  * xamarin/xamarin-android@607115fd5: LEGO: Merge pull request 8575
  * xamarin/xamarin-android@a1fd1b2cb: Localized file check-in by OneLocBuild Task (xamarin/xamarin-android#8570)
  * xamarin/xamarin-android@c020626b0: [Xamarin.Android.Build.Tasks] Update XA5207 for VSCode (xamarin/xamarin-android#8494)
  * xamarin/xamarin-android@b0aab545a: Bump to dotnet/installer/release/8.0.1xx@822071c28a 8.0.101-servicing.23578.14 (xamarin/xamarin-android#8558)


The .NET MAUI Support policy, which covers .NET Android, states:

> A major version of .NET MAUI receives support for a minimum of 6
> months after a successor (the next major release) ships.

meaning that a given version of .NET Android only needs to support
building `$(TargetFramework)` values for the current .NET Android
version and the previous .NET Android version.

Meanwhlie, from fd47b027:

> We currently have a hard dependency between:
> 
>   * `Xamarin.Android.Build.Tasks.dll`
>   * `libmonodroid.so`

…in order to safely build projects targeting the previous .NET Android
version with the current .NET Android version, the current .NET Android
version workload *includes the previous workload version contents*.

The `$(AndroidNetPreviousVersion)` MSBuild property specifies the
.NET Android SDK version, as obtained from `dotnet workllad list`,
which should be used to build previous `$(TargetFramework)` versions.

`$(AndroidNetPreviousVersion)` should be updated in
xamarin-android/main whenever a .NET servicing release for the previous
.NET version is shipped.

.NET Android 34.0.79 will be shipped as part of .NET 8.0.2.
Update `$(AndroidNetPreviousVersion)` to so that .NET 9 previews use
the latest .NET 8 workload contents.

Configuration.props

@@ -43,7 +43,7 @@
     <DebugType Condition=" '$(DebugType)' == '' ">portable</DebugType>
     <Deterministic Condition=" '$(Deterministic)' == '' ">True</Deterministic>
     <LangVersion Condition=" '$(LangVersion)' == '' ">latest</LangVersion>
-    <AndroidNetPreviousVersion Condition=" '$(AndroidNetPreviousVersion)' == '' ">34.0.56</AndroidNetPreviousVersion>
+    <AndroidNetPreviousVersion Condition=" '$(AndroidNetPreviousVersion)' == '' ">34.0.79</AndroidNetPreviousVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(HostOS)' == '' ">
     <HostOS Condition="$([MSBuild]::IsOSPlatform('windows'))">Windows</HostOS>