Fixes #1742 (emoji support) (#1745)

* Add test for Android emoji issue

See #1742

* Add a test for round trip emoji

It used to be fine because it was all modified UTF-8, but now need to test the conversion to normal UTF-8 and back.

* Update LiteCore

To get some tweaks to UTF-8 conversion

Author: borrrden

android/CouchbaseLite/src/androidTest/java/com/couchbase/lite/JavaTest.java

@@ -37,6 +37,7 @@ public class JavaTest extends BaseTest {
     // https://github.com/couchbase/couchbase-lite-android/issues/1453
     @Test
     public void testFLEncode() throws LiteCoreException {
+        testRoundTrip("Hello \uD83D\uDE3A World"); // 😺
         testRoundTrip(42L);
         testRoundTrip(Long.MIN_VALUE);
         testRoundTrip("Fleece");
@@ -49,6 +50,20 @@ public void testFLEncode() throws LiteCoreException {
         testRoundTrip(Math.PI);
     }
 
+    // https://github.com/couchbase/couchbase-lite-android/issues/1742
+    @Test
+    public void testDecodeEmoji() throws LiteCoreException {
+        // 0000: 44 f0 9f 98…: "😺"
+        // 0006: 80 03       : &"😺" (@0000)
+
+        byte[] realUtf8Data = new byte[] { (byte)0x44, (byte)0xF0, (byte)0x9F, (byte)0x98, (byte)0xBA,
+                (byte)0x00, (byte)0x80, (byte)0x03 };
+        FLValue flValue = FLValue.fromData(realUtf8Data);
+        assertNotNull(flValue);
+        Object obj = FLValue.toObject(flValue);
+        assertEquals("\uD83D\uDE3A", obj);
+    }
+
     private void testRoundTrip(Object item) throws LiteCoreException {
         Encoder encoder = new Encoder();
         assertNotNull(encoder);