Fix renaming files in clone volumes.

When an application running in the owner user tries to rename a file
that's located in a clone user volume, for example by modifying
RELATIVE_PATH, we need to make sure that we compute the new DATA
column correctly, by taking the existing location of the file into
account.

Bug: 199822693
Test: TEST_MAPPING, manual
Change-Id: Idab885dd78c75d12452319463dcc07b837502149
1 file changed