Revert "Revert "Move Gallery2 to androidx.""

This reverts commit fac21a096afbe8eb517726cf4f9f093eade87ddc.

We can reland this change now that prebuilts/sdk has been updated with the new SDK. (ag/3818779)

Bug: 76692459
Change-Id: I73f2ed3d61bc8756d1b7e4ea0e54c58227d5d506
21 files changed