Support nullable returns NativeModule methods returning Boxed Primitives

Summary:
Returning null from a NativeModule method that has a return type of `java.lang.Double` causes the program to crash. This diff instead makes that method call return `null` to JS. TurboModules already has this behaviour.

Changelog:
[Android][Fixed] - Support nullable returns NativeModule methods returning Boxed Primitives

Reviewed By: PeteTheHeat

Differential Revision: D18866872

fbshipit-source-id: 6049c4df6908f1d276c5674b7e06eb5e002a7976

Author: RSNara

ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp

@@ -223,13 +223,19 @@ MethodCallResult MethodInvoker::invoke(std::weak_ptr<Instance>& instance, alias_
 #define OBJECT_CASE(JNI_CLASS, ACTIONS) {                                 \
   auto jobject = env->CallObjectMethodA(module.get(), method_, args);     \
   throwPendingJniExceptionAsCppException();                               \
+  if (!jobject) {                                                         \
+    return folly::dynamic(nullptr);                                       \
+  }                                                                       \
   auto result = adopt_local(static_cast<JNI_CLASS::javaobject>(jobject)); \
   return folly::dynamic(result->ACTIONS());                               \
 }
 
 #define OBJECT_CASE_CASTING(JNI_CLASS, ACTIONS, RESULT_TYPE) {            \
   auto jobject = env->CallObjectMethodA(module.get(), method_, args);     \
   throwPendingJniExceptionAsCppException();                               \
+  if (!jobject) {                                                         \
+    return folly::dynamic(nullptr);                                       \
+  }                                                                       \
   auto result = adopt_local(static_cast<JNI_CLASS::javaobject>(jobject)); \
   return folly::dynamic(static_cast<RESULT_TYPE>(result->ACTIONS()));     \
 }