wifi: Support 11b only mode

upgrade @1.4::ConnectionCapabilities to include legacyMode, update
corresponding 1.3 VTS test and add new 1.4 VTS test files

Bug: 163912712
Test: atest VtsHalWifiSupplicantV1_0TargetTest \
            VtsHalWifiSupplicantV1_1TargetTest \
	    VtsHalWifiSupplicantV1_2TargetTest \
	    VtsHalWifiSupplicantV1_3TargetTest \
	    VtsHalWifiSupplicantV1_4TargetTest
Test: manual test with 11b only AP to confirm 11b mode is detected and
passed to throughput predictor correctly.

Change-Id: Id4fd567401289091a5d74a770e759eee326c3873
diff --git a/wifi/supplicant/1.4/ISupplicantStaIface.hal b/wifi/supplicant/1.4/ISupplicantStaIface.hal
new file mode 100644
index 0000000..28ef912
--- /dev/null
+++ b/wifi/supplicant/1.4/ISupplicantStaIface.hal
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.wifi.supplicant@1.4;
+
+import @1.0::SupplicantStatus;
+import @1.3::ISupplicantStaIface;
+
+/**
+ * Interface exposed by the supplicant for each station mode network
+ * interface (e.g wlan0) it controls.
+ */
+interface ISupplicantStaIface extends @1.3::ISupplicantStaIface {
+
+    /**
+     * Get Connection capabilities
+     *
+     * @return status Status of the operation, and connection capabilities.
+     *         Possible status codes:
+     *         |SupplicantStatusCode.SUCCESS|,
+     *         |SupplicantStatusCode.FAILURE_UNKNOWN|,
+     */
+    getConnectionCapabilities_1_4()
+        generates (SupplicantStatus status, ConnectionCapabilities capabilities);
+
+};