Increase callback waiting time to fix test flakiness.

1s buffer is not long enough if the DUT is running very slowly. We are still seeing Presubmit flakiness with 1s timeout.

Change-Id: I0560f05aa23addadebf71d78a45dce6ee947120e
Flag: EXEMPT test
Tests: Presubmit
Bug: b/385998282
1 file changed