[4/N] APIs for verification policy and failure reasons

+ Define failure reason codes
+ Define policy constants
+ Removed VERIFICATION_FAILED_REASON_NETWORK_LIMITED
+ Add getter/setter for session and global policy overrides
+ Allow Shell to have VERIFICATION_AGENT permission

FLAG: android.content.pm.verification_service

BUG: 360129103
BUG: 360129657

Test: atest CtsPackageManagerTestCases:VerifierServiceTest

Change-Id: Ibfeb88ad71677c4c61476c8af6b8607c131072f6
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 408ed1e..b385aaa 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -924,6 +924,7 @@
 
     <!-- Permission required for CTS test - CtsPackageManagerTestCases-->
     <uses-permission android:name="android.permission.DOMAIN_VERIFICATION_AGENT" />
+    <uses-permission android:name="android.permission.VERIFICATION_AGENT" />
 
     <!-- Permission required for Cts test - CtsInputTestCases -->
     <uses-permission