global: optimize imports

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

tunnel/src/main/java/com/wireguard/android/util/RootShell.java

@@ -5,13 +5,11 @@
 
 package com.wireguard.android.util;
 
-import com.wireguard.util.NonNullForAll;
-
 import android.content.Context;
-import androidx.annotation.Nullable;
 import android.util.Log;
 
 import com.wireguard.android.util.RootShell.RootShellException.Reason;
+import com.wireguard.util.NonNullForAll;
 
 import java.io.BufferedReader;
 import java.io.File;
@@ -22,6 +20,8 @@ import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.UUID;
 
+import androidx.annotation.Nullable;
+
 /**
  * Helper class for running commands as root.
  */