Crash pairing keyboard/mouse on N5

The crash is caused by read the source string out of  bound.
Should limit the length to copy less than source string length.
should use the
MIN(SDP_DISC_ATTR_LEN(p_curr_attr->attr_len_type), SDP_MAX_ATTR_LEN);
as the length to copy.

bug:12166360
Change-Id: I871d7dcaa8bf73aa27e9088417b35b677924bebd