Migrate PARENT column from legacy MediaProvider's database

PARENT column is computed based on the path of the file when database
row is inserted. For migrated db rows, this will be set to NULL.
To avoid NULL values, this CL migrates these columns from legacy
MediaProvider's database.

Bug: 162490053
Test: atest MediaProviderTests
Change-Id: Idb9d286d1594448bbd446239df41ba64b6cb9b20
(cherry picked from commit 19da95bfa8ef6f852d36607d2884797551f5f245)
1 file changed