am c7510581: SipService: add log control, suppress ping log.

Merge commit 'c7510581b81d63536db7d46ca8533106c8cf57c6' into gingerbread-plus-aosp

* commit 'c7510581b81d63536db7d46ca8533106c8cf57c6':
  SipService: add log control, suppress ping log.