Update signature files to the new format

The new format is described in tools/metalava/FORMAT.md.

Fixes: 116589402 Switch signature files over to the v2 format
Fixes: 112626813 Drop "synchronized" modifier from the signature format
Fixes: 122358225 Omit overriding methods that only differ in final [...]
Fixes: 73088715 API Review: Need doclava to output nullability
Fixes: 79739773 API Review: Metalava enforcing constants are constant
Exempt-From-Owner-Approval: Large-scale tooling change
Test: make sdk, make update-api, make checkapi
Change-Id: Ia248aece5250e84e47c815c601133b698bf644c2
diff --git a/libs/usb/api/current.txt b/libs/usb/api/current.txt
index 8488db5..f17b65a 100644
--- a/libs/usb/api/current.txt
+++ b/libs/usb/api/current.txt
@@ -1,12 +1,13 @@
+// Signature format: 2.0
 package com.android.future.usb {
 
   public class UsbAccessory {
-    method public java.lang.String getDescription();
-    method public java.lang.String getManufacturer();
-    method public java.lang.String getModel();
-    method public java.lang.String getSerial();
-    method public java.lang.String getUri();
-    method public java.lang.String getVersion();
+    method public String getDescription();
+    method public String getManufacturer();
+    method public String getModel();
+    method public String getSerial();
+    method public String getUri();
+    method public String getVersion();
   }
 
   public class UsbManager {
@@ -16,9 +17,9 @@
     method public boolean hasPermission(com.android.future.usb.UsbAccessory);
     method public android.os.ParcelFileDescriptor openAccessory(com.android.future.usb.UsbAccessory);
     method public void requestPermission(com.android.future.usb.UsbAccessory, android.app.PendingIntent);
-    field public static final java.lang.String ACTION_USB_ACCESSORY_ATTACHED = "android.hardware.usb.action.USB_ACCESSORY_ATTACHED";
-    field public static final java.lang.String ACTION_USB_ACCESSORY_DETACHED = "android.hardware.usb.action.USB_ACCESSORY_DETACHED";
-    field public static final java.lang.String EXTRA_PERMISSION_GRANTED = "permission";
+    field public static final String ACTION_USB_ACCESSORY_ATTACHED = "android.hardware.usb.action.USB_ACCESSORY_ATTACHED";
+    field public static final String ACTION_USB_ACCESSORY_DETACHED = "android.hardware.usb.action.USB_ACCESSORY_DETACHED";
+    field public static final String EXTRA_PERMISSION_GRANTED = "permission";
   }
 
 }
diff --git a/libs/usb/api/removed.txt b/libs/usb/api/removed.txt
index e69de29..d802177 100644
--- a/libs/usb/api/removed.txt
+++ b/libs/usb/api/removed.txt
@@ -0,0 +1 @@
+// Signature format: 2.0
diff --git a/libs/usb/api/system-current.txt b/libs/usb/api/system-current.txt
index e69de29..d802177 100644
--- a/libs/usb/api/system-current.txt
+++ b/libs/usb/api/system-current.txt
@@ -0,0 +1 @@
+// Signature format: 2.0
diff --git a/libs/usb/api/system-removed.txt b/libs/usb/api/system-removed.txt
index e69de29..d802177 100644
--- a/libs/usb/api/system-removed.txt
+++ b/libs/usb/api/system-removed.txt
@@ -0,0 +1 @@
+// Signature format: 2.0
diff --git a/libs/usb/api/test-current.txt b/libs/usb/api/test-current.txt
index e69de29..d802177 100644
--- a/libs/usb/api/test-current.txt
+++ b/libs/usb/api/test-current.txt
@@ -0,0 +1 @@
+// Signature format: 2.0
diff --git a/libs/usb/api/test-removed.txt b/libs/usb/api/test-removed.txt
index e69de29..d802177 100644
--- a/libs/usb/api/test-removed.txt
+++ b/libs/usb/api/test-removed.txt
@@ -0,0 +1 @@
+// Signature format: 2.0