Create explicit `$(AndroidEnableFastDeployment)` property

[jpobst]

Today, our "fast dev" experience is controlled via the $(EmbedAssembliesInApk) MSBuild property (and others?). This is confusing as the name does not give a hint of "fast dev".

It would be nice to alias this property as something like $(AndroidEnableFastDeployment) that is clearer to its purpose.