ASACORE-1192 assert in _MDNSPacket::AddAnswer.

The crash was caused due to adding the same answer twice, leading to number of records exceeding the expected limits.

Change-Id: I21d5540b50c0f4d2dccaea911053be58daea3799
Signed-off-by: Sheshambika Venkateshwaran <sheshamb@qce.qualcomm.com>
Merge "ASACORE-1192 assert in _MDNSPacket::AddAnswer." into RB14.12