Beside allowing AES-GCM again, this adds AES-192 again.

ASTERISK-27356

Change-Id: Ia97a435faf26300335d9552fa676b5d17e5f7233

Asterisk is able to use libSRTP 2.0.x. However since libSRTP 2.1.x, the macro
SRTP_AES_ICM got renamed to SRTP_AES_ICM_128. Beside to still compile with
previous versions of libSRTP, this change allows libSRTP 2.1.x as well.

ASTERISK-27253 #close

Change-Id: I2e6eb3c3bc844fee8a624060a2eb6f182dc70315

ASTERISK-25294 #close
Reported by: Tzafrir Cohen

ASTERISK-26976 #close
Reported by: Alex

Change-Id: I789b1c3d1ed31365bbd9339fa58ef36f48833c40