Don't crash on failed DataLoader creation.

Bug: 193749733
Fixes: 193749733
Test: atest GtsIncrementalInstallProxyHostTestCases
Change-Id: I65d9f7d6a5abed5eae42518c87235dc791a06a5f
diff --git a/libdataloader/DataLoaderConnector.cpp b/libdataloader/DataLoaderConnector.cpp
index 91ff74e..f5f82ea 100644
--- a/libdataloader/DataLoaderConnector.cpp
+++ b/libdataloader/DataLoaderConnector.cpp
@@ -318,11 +318,11 @@
     DataLoaderConnector(const DataLoaderConnector&) = delete;
     DataLoaderConnector(const DataLoaderConnector&&) = delete;
     virtual ~DataLoaderConnector() {
-        CHECK(mDataLoader);
-        if (mDataLoader->onDestroy) {
+        if (mDataLoader && mDataLoader->onDestroy) {
             mDataLoader->onDestroy(mDataLoader);
+            checkAndClearJavaException(__func__);
         }
-        checkAndClearJavaException(__func__);
+        mDataLoader = nullptr;
 
         JNIEnv* env = GetOrAttachJNIEnvironment(mJvm);