Fix test and lint

app/src/main/java/com/keylesspalace/tusky/view/EmojiKeyboard.java

@@ -5,6 +5,7 @@ import android.content.*;
 import android.util.*;
 import android.widget.*;
 import android.app.*;
+import android.text.*;
 import com.google.android.material.tabs.TabLayout;
 import com.google.android.material.tabs.TabLayoutMediator;
 import androidx.viewpager2.widget.ViewPager2;
@@ -90,12 +91,12 @@ public class EmojiKeyboard extends LinearLayout {
         if(size > MAX_RECENTS_ITEMS) {
             List<String> list = new ArrayList<String>(recents);
             list = list.subList(size - MAX_RECENTS_ITEMS, size);
-            joined = String.join(RECENTS_DELIM, list);
+            joined = TextUtils.join(RECENTS_DELIM, list);
             if(isSticky) {
                 recents = new LinkedHashSet<String>(list);
             }
         } else {
-            joined = String.join(RECENTS_DELIM, recents);
+            joined = TextUtils.join(RECENTS_DELIM, recents);
         }
         
         editor.putString(preferenceKey, joined);

app/src/test/java/com/keylesspalace/tusky/FilterTest.kt

@@ -11,6 +11,7 @@ import com.keylesspalace.tusky.fragment.SFragment
 import com.keylesspalace.tusky.network.MastodonApi
 import com.nhaarman.mockitokotlin2.mock
 import okhttp3.Request
+import okio.Timeout
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Before
@@ -57,7 +58,9 @@ class FilterTest {
             override fun request(): Request {
                 throw Error("not implemented")
             }
-
+            override fun timeout(): Timeout {
+                throw Error("not implemented")
+            }
             override fun enqueue(callback: Callback<List<Filter>>) {
                 callback.onResponse(
                         this,