Fix SoftInputShowHideHistory entry seq number representation

The sequence number will be reset from 0 when calling dumpsys input_method.
This increasing number should be stored into history Entry.

Fix: 154115116
Test: Use `adb shell dumpsys input_method` command multple times,
      Observe if the sequence number of SoftInputShowHidHistory entry
      is increasing.
Change-Id: Ic8c3afd8eb6748012edc860156c9f9aa78e2d4a6