[Xamarin.Android.Build.Tasks] Always create the debug.keystore

[dellis1972]

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=61065

If a user sets the $(AndroidKeyStore) to True for a
debug configuration they will get the following error.

[MESSAGE] jarsigner error: java.lang.RuntimeException: keystore load: /Users/$(user)/.local/share/Xamarin/Mono for Android/debug.keystore (No such file or directory)

Note this will only happen if they have NEVER build with
$(AndroidKeyStore) set to False. This is because we
don't always generate the debug.keystore.

So rather than hitting this issue we should always generate the
debug.keystore regardless of what the setting for $(AndroidKeyStore)
is. This commit splits out the keystore generation into its own
target. This target will check the existance of the file and
generate it if required. We also move all the debug key property
values into Properties so that they can be updated in one place.

[jonpryor]

This PR confuses me.

The original bug is that the Mono.Android.DebugRuntime*.apk shared runtime is signed with the "debug key," which isn't always created. If it hasn't been created, then package installation fails.

Additionally, the shared runtime creation logic within androidtools hardcodes the values used here, e.g. androiddebugkey as the jarsigner key alias.

Using $(_ApkDebugKeyAlias) to store androiddebugkey and then allowing $(_ApkDebugKeyAlias) to be overridden -- as the //CreateProperty/Output[@PropertyName='_ApkDebugKeyAlias']/@Condition supports -- is a recipe for future errors, as some enterprising developer decides to override $(_ApkDebugKeyAlias) within their .csproj and then wonders why things break in wonderful and mysterious ways.

I would prefer that the <AndroidCreateDebugKey/> invocation just hardcoded all the values. It's the "debug" key; we control it.

[jonpryor]

Why is this DependsOnTargets required? The only caller -- _ResolveAndroidSigningKey -- has $(_OnResolveMonoAndroidSdks) within its DependsOnTargets anyway.

[dellis1972]

@jonpryor I removed the properties.. One thing to note.. our assumption that CreateProperty does NOT override command line arguments is find for msbuild but NOT for xbuild. It just happily overwrites the values. So I have had to leave the condition on the _ApkDebugKeyStore CreateProperty call.

[EmilAlipiev]

Hi, interestingly it also fails if i refer to another keystore file. VS still looking for debug.keystore. please see the forum post more information.