[AndroidManifest.xml] Determine which attributes to expose in Mono.Android.

[jpobst]

Context: #8272

Previously, we created a process for automatically determining the possible attributes for elements in AndroidManifest.xml and generating the Mono.Android [Application], [Activity], etc. attributes for users to consume. At the time, we merely created the process, but did not use it to expose any new attributes that have been added in previous Android API levels that we never added.

We should create a list of all attributes we are missing, and then determine which of them we want to expose for users. Note that our process that goes directly to the source finds many attributes that Android does not publicly document. Thus we will need to evaluate each attribute to determine if we want to expose it.