Logd: include app package name in selinux metadata

Note: denial metadata is currently only included on debug builds.

avc: denied { read } for comm="getprop" name="u:object_r:net_dns_prop:s0"
dev="tmpfs" ino=19605 scontext=u:r:untrusted_app:s0:c164,c256,c512,c768
tcontext=u:object_r:net_dns_prop:s0 tclass=file permissive=0 b/12345678
app=android.selinuxtargetsdkcurrent.cts

Bug: 9496886
Bug: 68016944
Test: cts-tradefed run cts -m CtsSelinuxTargetSdkCurrentTestCases
Change-Id: I1700722a45b75d22f17ba4edc7b95cbaf99fdda8