Update and refactor storage service syncing.

Switched to proto3, updated protos, and generally refactored things to
make it easier to add new storage record types.

app/src/test/java/org/thoughtcrime/securesms/testutil/TestHelpers.java

@@ -0,0 +1,54 @@
+package org.thoughtcrime.securesms.testutil;
+
+import com.annimon.stream.Stream;
+import com.google.common.collect.Sets;
+
+import org.thoughtcrime.securesms.util.Conversions;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+import static junit.framework.TestCase.assertTrue;
+import static org.junit.Assert.assertEquals;
+
+public final class TestHelpers {
+
+  private TestHelpers() {}
+
+
+  public static byte[] byteArray(int a) {
+    return Conversions.intToByteArray(a);
+  }
+
+  public static List<byte[]> byteListOf(int... vals) {
+    List<byte[]> list = new ArrayList<>(vals.length);
+
+    for (int i = 0; i < vals.length; i++) {
+      list.add(Conversions.intToByteArray(vals[i]));
+
+    }
+    return list;
+  }
+
+  @SafeVarargs
+  public static <E> Set<E> setOf(E... values) {
+    return Sets.newHashSet(values);
+  }
+
+  public static void assertByteListEquals(List<byte[]> a, List<byte[]> b) {
+    assertEquals(a.size(), b.size());
+
+    List<ByteBuffer> aBuffer = Stream.of(a).map(ByteBuffer::wrap).toList();
+    List<ByteBuffer> bBuffer = Stream.of(b).map(ByteBuffer::wrap).toList();
+
+    assertTrue(aBuffer.containsAll(bBuffer));
+  }
+
+  public static <E> void assertContentsEqual(Collection<E> a, Collection<E> b) {
+    assertEquals(a.size(), b.size());
+    assertTrue(a.containsAll(b));
+  }
+}