[DSRM] Fix for failing to perform data stall recovery soon after

       skipping data recovery action under poor network signal.

Symptom: If a data stall recovery is skipped under poor
         network signal strength for the very first time.
	 Then in the next iteration, data stall recovery is
	 skipped due to mIsValidNetwork flag remains false always.

Solution: Refactor the existing conditions for data stall recovery.

Bug: 249687945
Test: Manual test passed. See the correct time in log.
      Telephony sanity test passed. Result: b/270503972.

Signed-off-by: Diaesh Antony <diaeshantony@google.com>
Change-Id: I16abe882dfc965b7f48b37d79e5e678efbc490b0
Merged-In: I16abe882dfc965b7f48b37d79e5e678efbc490b0