DO NOT MERGE: Revert "Enable cross-user requests."

Revert "Re-enable cross-user test case."

Revert submission 15463074-enable-cross-user

Reason for revert: ShortManager has bumped their integration from sc-v2-dev to master, so there is no request for AppSearch to support multi-user in sc-v2-dev. Will revert this change and re-enable multi-user back in Android T.

Reverted Changes:
I93c083d83:Enable cross-user requests.
I5f61ae416:Re-enable cross-user test case.

Change-Id: I9e7f3ecd83497986fa476a3abecf1412c277194d
Merged-In: I38469ad5df100e90aba81bbdc82078b568301f09