fix mix-use of tBTA_AG_PEER_CODEC between BTM_SCO_CODEC_XXX and UUID_CODEC_XXX

Previously, tBTA_AG_PEER_CODEC is a uint type that used for both BTM_SCO_CODEC_XXX (in bit mask format) and UUID_CODEC_XXX (in index format).
Because 1 and 2 in bitmask and indexed value are the same, there are mixed use between BTM_SCO_CODEC and UUID_CODEC
Now separate the UUID_CODEC_XXX index format out to a different type to avoid mis-use.

Bug: 323409386
Bug: 315234036
Flag: Exempt, no value change
Test: atest bta_net_test
Change-Id: Ia73d4bcaf891ecd03496269e3c9793ed33c09892