API level 30 upgrade: AOSP WallpaperPicker

The AndroidManifest.xml and build.gradele files
have been updated so that the targetSdkVersion is
30.

Test: manual - the app builds successfully and
wallpapers can be changed and added without any
issues. The CTS provider test output is seen below:

================= Results ==================
=============== Consumed Time ==============
    arm64-v8a CtsProviderTestCases: 13m 19s
Total aggregated tests run time: 13m 19s
============== TOP 1 Slow Modules ==============
    arm64-v8a CtsProviderTestCases: 0.47 tests/sec [376 tests / 799893 msec]
============== Modules Preparation Times ==============
    arm64-v8a CtsProviderTestCases => prep = 12093 ms || clean = 2457 ms
Total preparation time: 12s  ||  Total tear down time: 2s
=======================================================
=============== Summary ===============
Total Run time: 15m 14s
1/1 modules completed
Total Tests       : 376
PASSED            : 362
FAILED            : 0
IGNORED           : 6
ASSUMPTION_FAILURE: 8
============== End of Results ==============

Change-Id: I2135ab451f8e30863c85415ff1d51cbe999515e3
2 files changed