Fix detection of GProx II cards and false detection of other cards (#3869)

* Fix detection of GProx II cards and false detection of other cards as GProx II
* Fix incorrect parity starting bit

Co-authored-by: あく <alleteam@gmail.com>

Author: Astrrra

lib/lfrfid/protocols/protocol_gproxii.c

@@ -39,11 +39,12 @@ void protocol_gproxii_free(ProtocolGProxII* protocol) {
 }
 
 uint8_t* protocol_gproxii_get_data(ProtocolGProxII* proto) {
-    return proto->data;
+    return proto->decoded_data;
 }
 
 void protocol_gproxii_decoder_start(ProtocolGProxII* protocol) {
     memset(protocol->data, 0, GPROXII_ENCODED_BYTE_FULL_SIZE);
+    memset(protocol->decoded_data, 0, GPROXII_DATA_SIZE);
     protocol->last_short = false;
 }
 
@@ -88,8 +89,9 @@ static bool protocol_gproxii_can_be_decoded(ProtocolGProxII* protocol) {
     if(bit_lib_get_bits(protocol->data, 0, 6) != 0b111110) return false;
 
     // Check always 0 parity on every 5th bit after preamble
-    if(bit_lib_test_parity(protocol->data, 5, GPROXII_ENCODED_BIT_SIZE, BitLibParityAlways0, 5))
+    if(!bit_lib_test_parity(protocol->data, 6, GPROXII_ENCODED_BIT_SIZE, BitLibParityAlways0, 5)) {
         return false;
+    }
 
     // Start GProx II decode
     bit_lib_copy_bits(protocol->decoded_data, 0, GPROXII_ENCODED_BIT_SIZE, protocol->data, 6);