global: Fix or suppress most lints/warnings

Signed-off-by: Samuel Holland <samuel@sholland.org>

app/src/main/java/com/wireguard/android/util/ClipboardUtils.java

@@ -9,7 +9,7 @@ import android.widget.TextView;
 import com.commonsware.cwac.crossport.design.widget.Snackbar;
 
 /**
- * Created by samuel on 12/30/17.
+ * Standalone utilities for interacting with the system clipboard.
  */
 
 public final class ClipboardUtils {

app/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java

@@ -23,6 +23,7 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
     private final Comparator<? super K> comparator;
     private final transient KeyList<K, E> keyList = new KeyList<>(this);
 
+    @SuppressWarnings("WeakerAccess")
     public ObservableSortedKeyedArrayList() {
         comparator = null;
     }
@@ -178,6 +179,7 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
         }
 
         @Override
+        @SuppressWarnings("EmptyMethod")
         public Spliterator<K> spliterator() {
             return super.spliterator();
         }

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

@@ -9,14 +9,14 @@ import com.wireguard.android.Application.ApplicationContext;
 import com.wireguard.android.Application.ApplicationScope;
 import com.wireguard.android.R;
 
-import java.io.BufferedWriter;
 import java.io.BufferedReader;
-import java.io.OutputStreamWriter;
-import java.io.InputStreamReader;
+import java.io.BufferedWriter;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
 import java.nio.charset.StandardCharsets;
-import java.util.List;
+import java.util.Collection;
 import java.util.UUID;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -38,11 +38,10 @@ public class RootShell {
 
     private final String exceptionMessage;
     private final String preamble;
-
+    private Process process;
+    private BufferedReader stderr;
     private BufferedWriter stdin;
     private BufferedReader stdout;
-    private BufferedReader stderr;
-    private Process process;
 
     @Inject
     public RootShell(@ApplicationContext final Context context) {
@@ -141,7 +140,7 @@ public class RootShell {
      * @param command Command to run as root.
      * @return The exit value of the last command run, or -1 if there was an internal error.
      */
-    public int run(final List<String> output, final String command)
+    public int run(final Collection<String> output, final String command)
             throws ErrnoException, IOException, NoRootException {
         ensureRoot();