Allow processes in the "system" group to read /metadata/ota.

lpdumpd runs as "system", not "root". Adjust the DAC permissions of
/metadata/ota so it can call SnapshotManager::Dump.

Bug: 291083311
Test: lpdump
Change-Id: I97fd7eb2055cf6d31fd42f1021e2f99edbdb838a
1 file changed