Merge changes from topic "RKP_metrics"

* changes:
  Add Security Level and the four key states to RkpPoolStats
  Remove obsolete keystore2 atoms.
diff --git a/stats/atoms.proto b/stats/atoms.proto
index 9db3331..874b6f6 100644
--- a/stats/atoms.proto
+++ b/stats/atoms.proto
@@ -12552,6 +12552,7 @@
     ART_COMPILATION_REASON_BOOT_AFTER_OTA = 17;
     ART_COMPILATION_REASON_PREBUILT = 18;
     ART_COMPILATION_REASON_CMDLINE = 19;
+    ART_COMPILATION_REASON_VDEX = 20;
 }
 
 // Indicates which kind of measurement ART is reporting.