More work on issue #73301635: Ability to extract device configuration

Now include Gl extensions (thanks to whoever wrote the code
I copied!).

Tweak the protos a bit to include missing info and correct
some things.

Add some new test APIs that are needed for CTS.

Bug: 73301635
Test: atest CtsActivityManagerDeviceTestCases:ActivityManagerGetConfigTests
Change-Id: Ie3f8173d217468246e8b6c7f45b7cbfcb352d60f