Add mimeGroup tag to intent filters

Intent filters can now have a |data| element
with a |mimeGroup| attribute on it. In a future
CL, the user can add mimeTypes to a mimeGroup,
which will cause the intent-filter to match all those
mimeTypes.

Bug: 134736173
Bug: 136635677
Test: atest android.content.pm.PackageParserTest#testPackageWithIntentFilters*

Change-Id: Ie44dc441e00c29d735814564b7f27b341a69a860