lmkd: Restrict process record modifications to the client that created it

Associate each registered process with the PID of the lmkd client that
registered it to prevent one client from updating records of another
client.

Bug: 129011369
Test: boot and verify native service registration
Change-Id: Id8ca7bb6314df225d04da6469b523d2cdc237eaa
Signed-off-by: Suren Baghdasaryan <surenb@google.com>