NFC on Android: Fix crash on restart of an app in debug build

Task-number: QTBUG-59343
Change-Id: Ib474db8e9a8d38b3d5668499f838cb8d38e10625
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

src/nfc/android/androidjninfc.cpp

@@ -88,7 +88,6 @@ QAndroidJniObject getTag(const QAndroidJniObject &intent)
 {
     QAndroidJniObject extraTag = QAndroidJniObject::getStaticObjectField("android/nfc/NfcAdapter", "EXTRA_TAG", "Ljava/lang/String;");
     QAndroidJniObject tag = intent.callObjectMethod("getParcelableExtra", "(Ljava/lang/String;)Landroid/os/Parcelable;", extraTag.object<jstring>());
-    Q_ASSERT_X(tag.isValid(), "getTag", "could not get Tag object");
     return tag;
 }
 

src/nfc/qnearfieldtarget_android.cpp

@@ -401,6 +401,8 @@ void NearFieldTarget::updateTechList()
     // Getting tech list
     QAndroidJniEnvironment env;
     QAndroidJniObject tag = AndroidNfc::getTag(m_intent);
+    Q_ASSERT_X(tag.isValid(), "updateTechList", "could not get Tag object");
+
     QAndroidJniObject techListArray = tag.callObjectMethod("getTechList", "()[Ljava/lang/String;");
     if (!techListArray.isValid()) {
         handleTargetLost();
@@ -493,6 +495,8 @@ QAndroidJniObject NearFieldTarget::getTagTechnology(const QString &tech) const
 
     // Getting requested technology
     QAndroidJniObject tag = AndroidNfc::getTag(m_intent);
+    Q_ASSERT_X(tag.isValid(), "getTagTechnology", "could not get Tag object");
+
     const QString sig = QString::fromUtf8("(Landroid/nfc/Tag;)L%1;");
     QAndroidJniObject tagTech = QAndroidJniObject::callStaticObjectMethod(techClass.toUtf8().constData(), "get",
             sig.arg(techClass).toUtf8().constData(), tag.object<jobject>());