accounts: resolve error-prone warnings

- missing @Override annotations
 - inner classes should be static if possible

Bug: 38496625
Test: build
Change-Id: Ic6a647b894036266dfa8f9908cec6049952cd38d

services/core/java/com/android/server/accounts/AccountAuthenticatorCache.java

@@ -53,6 +53,7 @@ import java.io.IOException;
                 AccountManager.AUTHENTICATOR_ATTRIBUTES_NAME, sSerializer);
     }
 
+    @Override
     public AuthenticatorDescription parseServiceAttributes(Resources res,
             String packageName, AttributeSet attrs) {
         TypedArray sa = res.obtainAttributes(attrs,
@@ -81,11 +82,13 @@ import java.io.IOException;
     }
 
     private static class MySerializer implements XmlSerializerAndParser<AuthenticatorDescription> {
+        @Override
         public void writeAsXml(AuthenticatorDescription item, XmlSerializer out)
                 throws IOException {
             out.attribute(null, "type", item.type);
         }
 
+        @Override
         public AuthenticatorDescription createFromXml(XmlPullParser parser)
                 throws IOException, XmlPullParserException {
             return AuthenticatorDescription.newKey(parser.getAttributeValue(null, "type"));

services/core/java/com/android/server/accounts/AccountManagerService.java

@@ -4944,6 +4944,7 @@ public class AccountManagerService
                 this.userDebugDbInsertionPoint = userDebugDbInsertionPoint;
             }
 
+            @Override
             public void run() {
                 SQLiteStatement logStatement = userAccount.statementForLogging;
                 logStatement.bindLong(1, accountId);
@@ -6060,7 +6061,7 @@ public class AccountManagerService
         }
     }
 
-    private class NotificationId {
+    private static class NotificationId {
         final String mTag;
         private final int mId;
 

services/core/java/com/android/server/accounts/AccountsDb.java

@@ -1321,6 +1321,7 @@ class AccountsDb implements AutoCloseable {
         }
     }
 
+    @Override
     public void close() {
         mDeDatabase.close();
     }