Sync framework from jetpack.

Included changes:
* 44f446f: Update getSchemaType() to be consistent with other usages
* 1a96f7f: Update docs in GenericDocument to an alternative visible to platform
* e4640c3: Fixes a grammatical issue
* 1ea6307: Manage visibility settings
* 8fa4956: Minor fixes to AppSearchImpl
* 7464be0: Adapt to new Icing Lib IndexingConfig name

Now includes a text file with the changeid of the jetpack HEAD at time
of export to make it easier to create the above "Included changes" list
in the future.

Bug: 162450968
Test: AppSearchManagerTest
Change-Id: I85909a44ac2677170872990452d2ab48ce71c1aa