bluedroid: Fix build with gcc 4.8+

Use -Wno-error=unused-parameter with gcc >= 4.8

Change-Id: I330a56b0363b90118628bc3b30451f8921ca6f60
Signed-off-by: Bernhard Rosenkränzer <Bernhard.Rosenkranzer@linaro.org>
bluedroid: Fix build for juice-aosp

This is a workaround for
In file included from
external/bluetooth/bluedroid/bta/./dm/bta_dm_act.c:40:0:
In function 'memcpy',
inlined from 'bta_dm_search_start.constprop.15' at
external/bluetooth/bluedroid/bta/./dm/bta_dm_act.c:1124:15,
inlined from 'bta_dm_rs_cback.part.11' at
external/bluetooth/bluedroid/bta/./dm/bta_dm_act.c:3147:28,
inlined from 'bta_dm_rs_cback' at
external/bluetooth/bluedroid/bta/./dm/bta_dm_act.c:3140:13:
bionic/libc/include/string.h:114:31: error: call to
'__memcpy_overlap_error' declared with attribute error: memcpy called
with overlapping regions

Change-Id: Ia14b3389cc434d3d3e4af3e84ab66fd47544aa7d
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>