move some log spilling below DEBUG

Change-Id: I5a8b269782a733bdb75cf38120ae255995f75e2c
protect unregisterReceiver method
unregister the same twice will lead to an IllegalArgumentException

Change-Id: Ie29065d8c1ae3ad8d1dfdebeaf0b17f052ba8fe5
framework/base: Handle ASSOC-REJECT events

Disable current network and enable other saved networks(if any)
once number of ASSOC-REJECTs on an attempt to connect to a corresponding
network exceeds the threshold.

Change-Id: Iac3c1596aa800d93c55b0ac5d8070a058c3842bd