Missing activity attribute LockTaskMode

[sdebruyn]

Steps to Reproduce

1. Create a new Xamarin.Android app, select "Latest and greatest" during the template wizard
2. Change the target framework and target API level to 27
3. Change the minimum API level to 23
4. Go to MainActivity.cs, add LockTaskMode to the Activity attribute

Android attribute: https://developer.android.com/reference/android/R.attr#lockTaskMode

Expected Behavior

The attribute is found.

Actual Behavior

The attribute doest not exist.

Version Information

=== Visual Studio Enterprise 2017 for Mac ===

Version 7.6.10 (build 27)
Installation UUID: e1324239-09f8-4ef0-841d-818a176fdfbd
Runtime:
	Mono 5.12.0.309 (2018-02/39d89a335c8) (64-bit)
	GTK+ 2.24.23 (Raleigh theme)
	Xamarin.Mac 4.4.1.178 (master / eeaeb7e6)

	Package version: 512000309

=== NuGet ===

Version: 4.3.1.4445

=== .NET Core ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
	2.1.2
	2.1.1
	2.1.0
	2.0.7
	2.0.5
SDK: /usr/local/share/dotnet/sdk/2.1.302/Sdks
SDK Versions:
	2.1.302
	2.1.301
	2.1.300
	2.1.200
	2.1.4
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/5.12.0/lib/mono/msbuild/15.0/bin/Sdks

=== Xamarin.Profiler ===

Version: 1.6.3
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Apple Developer Tools ===

Xcode 10.1 (14460.46)
Build 10B61

=== Xamarin.Mac ===

Version: 5.0.0.0 (Visual Studio Enterprise)
Hash: b40230c0
Branch: 
Build date: 2018-09-27 11:41:37-0400

=== Xamarin.iOS ===

Version: 12.0.0.15 (Visual Studio Enterprise)
Hash: 84552a46
Branch: xcode10
Build date: 2018-09-17 21:54:33-0400

=== Xamarin.Android ===

Version: 9.0.0.20 (Visual Studio Enterprise)
Android SDK: /Users/sam/Library/Android/sdk
	Supported Android versions:
		5.0 (API level 21)
		6.0 (API level 23)
		7.0 (API level 24)
		7.1 (API level 25)
		8.0 (API level 26)
		8.1 (API level 27)

SDK Tools Version: 26.1.1
SDK Platform Tools Version: 28.0.1
SDK Build Tools Version: 28.0.3

Java SDK: /usr
java version "1.8.0_172"
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)

Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

=== Xamarin Inspector ===

Version: 1.4.3
Hash: db27525
Branch: 1.4-release
Build date: Mon, 09 Jul 2018 21:20:18 GMT
Client compatibility: 1

=== Build Information ===

Release ID: 706100027
Git revision: 94dbd4d35daaa5a2ff6a51c3fd5cbb2308bd83ea
Build date: 2018-10-18 16:34:31+00
Build branch: release-7.6
Xamarin extensions: 3a9afc960ba73e5862829e8a0cd9369bcca43d70

=== Operating System ===

Mac OS X 10.14.0
Darwin 18.0.0 Darwin Kernel Version 18.0.0
    Wed Aug 22 20:13:40 PDT 2018
    root:xnu-4903.201.2~1/RELEASE_X86_64 x86_64

=== Enabled user installed extensions ===

Android Signature Tool 2.1.2
Gist Ide Information 1.1.0
MSBuild Editor 2.0.4
NuGet Package Explorer 0.2
NuGet Package Management Extensions 0.14
xUnit.NET 2 testing framework support 0.7.5

Log File

Not applicable.

[JonDouglas]

I'm marking and closing this as a duplicate of #1891