[Xamarin.Android.Build.Tasks] ignore aapt/AndroidManifest.xml

[jonathanpeppers]

Context: https://stackoverflow.com/questions/41592744/function-of-aapt-androidmanifest-xml-in-aar
Fixes: #2141

Apparently Android Studio is now shipping a duplicate, pre-formatted
AndroidManifest.xml file, inside of AAR files. Its purpose is to be
used with aapt invocations, since errors may be thrown related to
{ or } characters.

Since this file may exist in AAR files used by Xamarin.Android, we
should ignore aapt/AndroidManifest.xml files the same way we ignore
them inside manifest or bin directories.

Changes:

• Added a IgnoredManifestDirectories list, since we are getting to a
  point where != && != && != would be a lot of noise.
• Switched the LINQ expression to simple foreach loop, which should
  also give a slight performance benefit.

[dellis1972]

Looks good. merge when green :)

[dellis1972]

@jonathanpeppers this broke you new test

  "/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/bin/TestDebug/temp/ExtraAaptManifest/UnnamedProject.csproj" (Build target) (1) ->
  (_CompileJava target) -> 
obj/Debug/android/src/mono/io/fabric/sdk/android/services/events/EventsStorageListenerImplementor.java(8,40): error : error: package io.fabric.sdk.android.services.events does not exist [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/bin/TestDebug/temp/ExtraAaptManifest/UnnamedProject.csproj] [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/build-tools/scripts/RunTests.targets]
obj/Debug/android/src/mono/io/fabric/sdk/android/services/events/EventsStorageListenerImplementor.java(8,40): error : io.fabric.sdk.android.services.events.EventsStorageListener [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/bin/TestDebug/temp/ExtraAaptManifest/UnnamedProject.csproj] [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/build-tools/scripts/RunTests.targets]
obj/Debug/android/src/mono/io/fabric/sdk/android/services/events/EventsStorageListenerImplementor.java(8,40): error : [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/bin/TestDebug/temp/ExtraAaptManifest/UnnamedProject.csproj] [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/build-tools/scripts/RunTests.targets]
  
      0 Warning(s)
      1 Error(s)

[jonathanpeppers]

Weird it didn't show up as a failed test.

Trying locally again, maybe it works on Windows-only.