Store restored aspect ratios for not yet installed packages in SharedPreferences.

UserAspectRatioBackupManager registers for updates on package added/removed.
Once package is added, data is read from SharedPreferences and restored user
aspect ratio is committed.

Data for apps which are not installed within 7 days is deleted.

Flag: com.android.window.flags.backup_and_restore_for_user_aspect_ratio_settings
Bug: 405901435
Bug: 408430597
Test: atest UserAspectRatioBackupManagerTest
Test: manual
Change-Id: Id4d8fee385a320370cce7d56910dc75fbfd8792b