Modify sepolicy for compos key changes

Add the compos_key_helper domain for the process which has access to
the signing key, make sure it can't be crashdumped. Also extend that
protection to diced & its HAL.

Rename compos_verify_key to compos_verify, because it doesn't verify
keys any more.

Move exec types used by Microdroid to file.te in the host rather than
their own dedicated files.

Bug: 218494522
Test: atest CompOsSigningHostTest CompOsDenialHostTest
Change-Id: I942667355d8ce29b3a9eb093e0b9c4f6ee0df6c1
diff --git a/apex/com.android.compos-file_contexts b/apex/com.android.compos-file_contexts
index 0502084..799c2c4 100644
--- a/apex/com.android.compos-file_contexts
+++ b/apex/com.android.compos-file_contexts
@@ -1,4 +1,5 @@
 (/.*)?                   u:object_r:system_file:s0
-/bin/compsvc             u:object_r:compos_exec:s0
-/bin/compos_verify_key   u:object_r:compos_verify_key_exec:s0
+/bin/compos_key_helper   u:object_r:compos_key_helper_exec:s0
+/bin/compos_verify       u:object_r:compos_verify_exec:s0
 /bin/composd             u:object_r:composd_exec:s0
+/bin/compsvc             u:object_r:compos_exec:s0