Android: stop composing before pasting new text

We have to exit composition mode before inserting text. Otherwise, the
state of the input method will be out of sync with the contents of the
text editor.

Task-number: QTBUG-61717
Change-Id: I58bf3988ae9e0acf3302e810e46bb0ebeda30d17
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/plugins/platforms/android/qandroidinputcontext.cpp

@@ -303,7 +303,7 @@ static jboolean paste(JNIEnv */*env*/, jobject /*thiz*/)
         return JNI_FALSE;
 
 #ifdef QT_DEBUG_ANDROID_IM_PROTOCOL
-    qDebug("@@@");
+    qDebug("@@@ PASTE");
 #endif
     return m_androidInputContext->paste();
 }
@@ -1138,6 +1138,7 @@ jboolean QAndroidInputContext::copyURL()
 
 jboolean QAndroidInputContext::paste()
 {
+    finishComposingText();
     m_cursorHandleShown = CursorHandleNotShown;
     sendShortcut(QKeySequence::Paste);
     return JNI_TRUE;