Allow fs-verity setup within system_server

The original fs-verity implementation requires CAP_SYS_ADMIN and thus
the actual setup is proxied through installd.  Instead, upstream
FS_IOC_ENABLE_VERITY ioctl checks write permission to inode, and thus
can happen in system_server.

Also, replace the old measure ioctl with FS_IOC_SET_VERITY_MEASUREMENT.
Note that although the number is name, they work differently.

Test: set ro.apk_verity.mode=2, in-progress CTS passed without denial
Bug: 112037636
Change-Id: I3e8d14321df8904dfed68b83aae8b3dd99c211ac
diff --git a/private/system_server.te b/private/system_server.te
index ae6d687..e183606 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -789,6 +789,13 @@
 # Allow invoking tools like "timeout"
 allow system_server toolbox_exec:file rx_file_perms;
 
+# Allow system process to setup and measure fs-verity
+allowxperm system_server apk_data_file:file ioctl {
+  FS_IOC_ENABLE_VERITY FS_IOC_MEASURE_VERITY
+};
+# Allow system process to access the keyring.
+allow system_server kernel:key search;
+
 # Postinstall
 #
 # For OTA dexopt, allow calls coming from postinstall.