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
1 file changed