Verify all quotas before updating the database

Verify all quotas before updating the database

Update quota multi-value in one request is not an atomic operation, so
even if a quota is invalid (e.g., volumes has a non-integer value),
some values may change but the response code is 400.

This patch will make sure the quota limits are of integer type for all
the requested quota keys before updating the database.

Closes-Bug: 1432972
Change-Id: If83af0a80489887098e52b03b9c4012e3ef061b5
(cherry picked from commit 197299985a52535ad995dbd111491b58462f140a)