AOSP/Camera2 - Update Storage method to be compatible with API 29

Test: manual - Ran the following on Sargo phone. Tested ability to take
photos and see those photos in the gallery afterwards. Tested viewing
photos in the film strip view in the Camera2 app after taking multiple
photos.

$ source build/envsetup.sh
$ lunch aosp_sargo-userdebug
$ make Camera2 -j
$ adb push out/target/product/sargo/product/app/Camera2/Camera2.apk
/product/app/Camera2

BUG: 143990993
Change-Id: I75f2e52ba1f3d1ff8ad7ec9dffe1b4e081e407ea
2 files changed