Avoid premature LE connection notifaction to app

To avoid premature connection notification to app, always wait for
LE read remote feature complete with success before the connection
event is sent to application.

This patch also deprecates the BTA_SKIP_BLE_READ_REMOTE_FEAT flag.
Since the remote feature request is now serialized and start encryption
won't be called until the connection is up, this flag is no longer
necessary and interferes with the new behaviour.

This is an extension of previous CL

Bug: 17326529
Change-Id: Icfd4c5dfdd9f89d1318ef429e132eb005abb1f64
8 files changed