Add rc file for wait_for_keymaster

Similar to update_verifier, define higher prio and use exec_start for
this binary.

Bug: 79492334
Test: Reboot test
Change-Id: I8d3133cabcc8d4cee8bdead310f2c18d8d07e9dd
diff --git a/Android.bp b/Android.bp
index a8934fc..556784f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -158,7 +158,10 @@
             ],
         },
     },
-    init_rc: ["vold.rc"],
+    init_rc: [
+        "vold.rc",
+        "wait_for_keymaster.rc",
+    ],
 
     required: [
         "mke2fs",
diff --git a/wait_for_keymaster.rc b/wait_for_keymaster.rc
new file mode 100644
index 0000000..9e83a93
--- /dev/null
+++ b/wait_for_keymaster.rc
@@ -0,0 +1,5 @@
+service wait_for_keymaster /system/bin/wait_for_keymaster
+    user root
+    group root system
+    priority -20
+    ioprio rt 0