Currently, with EATT enabled, when bt_gatt_read is called with multiple
handles first it'll try to use gatt_read_mult_vl, and if it fails
gatt_read_mult will be used to try again. Add option to skip
the gatt_read_mult_vl and use gatt_read_mult right away. This is needed
by tests that expect BT_ATT_OP_READ_MULT_REQ but support variable
lenght, thus don't return BT_ATT_ERR_NOT_SUPPORTED.
Removed fallback from read multiple vl to read multiple on
BT_ATT_ERR_NOT_SUPPORTED error.
This was affecting:
GATT/CL/GAR/BV-05-C, GATT/CL/GAR/BI-18-C, GATT/CL/GAR/BI-19-C,
GATT/CL/GAR/BI-20-C, GATT/CL/GAR/BI-21-C, GATT/CL/GAR/BI-22-C
Signed-off-by: Krzysztof Kopyściński <krzysztof.kopyscinski@codecoup.pl>