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/current.txt b/current.txt
index 594ceb6..b929f7d 100644
--- a/current.txt
+++ b/current.txt
@@ -777,3 +777,6 @@
 # HALs released in Android S
 # NOTE: waiting to freeze HALs until later in the release
 # NOTE: new HALs are recommended to be in AIDL
+57d183b10b13ec0a8e542c0b3d61991ae541c60e85dbbc5499bb21dfd068cbb8 android.hardware.wifi.supplicant@1.4::types
+17818b6b1952a75e4364ae82c534b9d2f5c0a9765a56256b16faa5a5cf45d3a8 android.hardware.wifi.supplicant@1.4::ISupplicant
+8342b5f6ec8f48ad2b741128aede010995d0b5709257b7ec09bb469b4f61ef1a android.hardware.wifi.supplicant@1.4::ISupplicantStaIface