apexd: mount "decompressed" on dm-verity

Decompressed apexes are treated as "pre-installed" because only
preinstalled "compressed" apexes become "decompressed" apexes. But when
mounting them, we'd need to mount them on dm-verity because their
payloads come from /data partition.

Bug: 184597312
Test: ApexTestCases
Change-Id: Ie0a42c36329b2c37ff0bf04158e1322413b0add3
1 file changed