Normalize public key uri in KeyListFragment

Find the explicit row id of the public key id given in the uri in
KeyListFragment and work with that. This way, passing in uris by
master key id, mail address, or any other criteria, works.

Might be a good idea to add an actual check if the row id is non-zero
here, but not sure how to do a "bad intent" thing

OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java

@@ -514,6 +514,26 @@ public class ProviderHelper {
         return masterKeyId;
     }
 
+    public static long getRowId(Context context, Uri queryUri) {
+        String[] projection = new String[]{KeyRings._ID};
+        Cursor cursor = context.getContentResolver().query(queryUri, projection, null, null, null);
+
+        long rowId = 0;
+        try {
+            if (cursor != null && cursor.moveToFirst()) {
+                int idCol = cursor.getColumnIndexOrThrow(KeyRings._ID);
+
+                rowId = cursor.getLong(idCol);
+            }
+        } finally {
+            if (cursor != null) {
+                cursor.close();
+            }
+        }
+
+        return rowId;
+    }
+
     /**
      * Get fingerprint of key
      */