Restarting PM timer for AG while reading OR writing

- Once AG receives any data(eg. AT commands) from
  remote device(HF) and sending the response to remote
  device, PM(Bluedroid power Manager) timer should be restarted
  (stop & start) for AG.

- Increased the sniff timer value to 7 seconds for AV & AG
  profiles to avoid sniff related IOT issues.

Change-Id: I8c1b79d272391b3fa34b193477a34d561f4c508d