USB: [API feedback] Add bitmask @IntDef annonation to setCurrentFunctions

Bug: 148285097
Test: Manual test: USB function switch: MTP, PTP, RNDIS, MIDI
Test: atest UsbTests
Test: atest UsbManagerTests
Change-Id: I27f8097b0a8174f7c1d14b856442e8962b56a906
diff --git a/api/system-current.txt b/api/system-current.txt
index 202d51f..fa3379f 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -3349,8 +3349,14 @@
     method @RequiresPermission(android.Manifest.permission.MANAGE_USB) public void setCurrentFunctions(long);
     field @RequiresPermission(android.Manifest.permission.MANAGE_USB) public static final String ACTION_USB_PORT_CHANGED = "android.hardware.usb.action.USB_PORT_CHANGED";
     field public static final String ACTION_USB_STATE = "android.hardware.usb.action.USB_STATE";
+    field public static final long FUNCTION_ACCESSORY = 2L; // 0x2L
+    field public static final long FUNCTION_ADB = 1L; // 0x1L
+    field public static final long FUNCTION_AUDIO_SOURCE = 64L; // 0x40L
+    field public static final long FUNCTION_MIDI = 8L; // 0x8L
+    field public static final long FUNCTION_MTP = 4L; // 0x4L
     field public static final long FUNCTION_NCM = 1024L; // 0x400L
     field public static final long FUNCTION_NONE = 0L; // 0x0L
+    field public static final long FUNCTION_PTP = 16L; // 0x10L
     field public static final long FUNCTION_RNDIS = 32L; // 0x20L
     field public static final String USB_CONFIGURED = "configured";
     field public static final String USB_CONNECTED = "connected";
diff --git a/core/java/android/hardware/usb/UsbManager.java b/core/java/android/hardware/usb/UsbManager.java
index b0d0b4c..f540bfb 100644
--- a/core/java/android/hardware/usb/UsbManager.java
+++ b/core/java/android/hardware/usb/UsbManager.java
@@ -18,6 +18,7 @@
 package android.hardware.usb;
 
 import android.Manifest;
+import android.annotation.LongDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.RequiresFeature;
@@ -337,12 +338,14 @@
      * Code for the mtp usb function. Passed as a mask into {@link #setCurrentFunctions(long)}
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_MTP = GadgetFunction.MTP;
 
     /**
      * Code for the ptp usb function. Passed as a mask into {@link #setCurrentFunctions(long)}
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_PTP = GadgetFunction.PTP;
 
     /**
@@ -356,24 +359,28 @@
      * Code for the midi usb function. Passed as a mask into {@link #setCurrentFunctions(long)}
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_MIDI = GadgetFunction.MIDI;
 
     /**
      * Code for the accessory usb function.
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_ACCESSORY = GadgetFunction.ACCESSORY;
 
     /**
      * Code for the audio source usb function.
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_AUDIO_SOURCE = GadgetFunction.AUDIO_SOURCE;
 
     /**
      * Code for the adb usb function.
      * {@hide}
      */
+    @SystemApi
     public static final long FUNCTION_ADB = GadgetFunction.ADB;
 
     /**
@@ -399,6 +406,20 @@
         FUNCTION_NAME_TO_CODE.put(UsbManager.USB_FUNCTION_NCM, FUNCTION_NCM);
     }
 
+    /** @hide */
+    @LongDef(flag = true, prefix = { "FUNCTION_" }, value = {
+            FUNCTION_NONE,
+            FUNCTION_MTP,
+            FUNCTION_PTP,
+            FUNCTION_RNDIS,
+            FUNCTION_MIDI,
+            FUNCTION_ACCESSORY,
+            FUNCTION_AUDIO_SOURCE,
+            FUNCTION_ADB,
+            FUNCTION_NCM,
+    })
+    public @interface UsbFunctionMode {}
+
     private final Context mContext;
     private final IUsbManager mService;
 
@@ -721,7 +742,7 @@
      */
     @SystemApi
     @RequiresPermission(Manifest.permission.MANAGE_USB)
-    public void setCurrentFunctions(long functions) {
+    public void setCurrentFunctions(@UsbFunctionMode long functions) {
         try {
             mService.setCurrentFunctions(functions);
         } catch (RemoteException e) {