Update references of "DONT_DELETE_DATA" to "DELETE_KEEP_DATA".

The flag PackageManager.DONT_DELETE_DATA was renamed to DELETE_KEEP_DATA
long ago in commit 7767eac.

Bug: 28343859
Test: n/a
Change-Id: I9e4079ec394f92a3e293df7b80b627e2b6130827
5 files changed