Do check for throttled before allowing sms is throttled

Bug: 406623065
Test: Manual verification of polling tests that device does not
      send out more than 1 sms in 3 minutes for polling
Test: atest DatagramDispatcherTest
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:dcf5c1b546ce3cc04823cd3a88d608efc5f2e870)
Merged-In: I78b4f5c78efd736a673e2b3ad8ef2f9ad6b357b7
Change-Id: I78b4f5c78efd736a673e2b3ad8ef2f9ad6b357b7