Remove pointless dynamic use of ASensorManager.

This was only done so it could use ASensorManager_getInstanceForPackage
on newer devices and ASensorManager_getInstance on older devices. We can
just use ASensorManager_getInstance on all devices and spare the mess.

native-activity/app/src/main/cpp/main.cpp

@@ -269,50 +269,6 @@ static void engine_handle_cmd(struct android_app* app, int32_t cmd) {
   }
 }
 
-/*
- * AcquireASensorManagerInstance(void)
- *    Workaround ASensorManager_getInstance() deprecation false alarm
- *    for Android-N and before, when compiling with NDK-r15
- */
-#include <dlfcn.h>
-ASensorManager* AcquireASensorManagerInstance(android_app* app) {
-  if (!app) return nullptr;
-
-  typedef ASensorManager* (*PF_GETINSTANCEFORPACKAGE)(const char* name);
-  void* androidHandle = dlopen("libandroid.so", RTLD_NOW);
-  auto getInstanceForPackageFunc = (PF_GETINSTANCEFORPACKAGE)dlsym(
-      androidHandle, "ASensorManager_getInstanceForPackage");
-  if (getInstanceForPackageFunc) {
-    JNIEnv* env = nullptr;
-    app->activity->vm->AttachCurrentThread(&env, nullptr);
-
-    jclass android_content_Context = env->GetObjectClass(app->activity->clazz);
-    jmethodID midGetPackageName = env->GetMethodID(
-        android_content_Context, "getPackageName", "()Ljava/lang/String;");
-    auto packageName =
-        (jstring)env->CallObjectMethod(app->activity->clazz, midGetPackageName);
-
-    const char* nativePackageName =
-        env->GetStringUTFChars(packageName, nullptr);
-    ASensorManager* mgr = getInstanceForPackageFunc(nativePackageName);
-    env->ReleaseStringUTFChars(packageName, nativePackageName);
-    app->activity->vm->DetachCurrentThread();
-    if (mgr) {
-      dlclose(androidHandle);
-      return mgr;
-    }
-  }
-
-  typedef ASensorManager* (*PF_GETINSTANCE)();
-  auto getInstanceFunc =
-      (PF_GETINSTANCE)dlsym(androidHandle, "ASensorManager_getInstance");
-  // by all means at this point, ASensorManager_getInstance should be available
-  assert(getInstanceFunc);
-  dlclose(androidHandle);
-
-  return getInstanceFunc();
-}
-
 /**
  * This is the main entry point of a native application that is using
  * android_native_app_glue.  It runs in its own thread, with its own
@@ -328,7 +284,7 @@ void android_main(struct android_app* state) {
   engine.app = state;
 
   // Prepare to monitor accelerometer
-  engine.sensorManager = AcquireASensorManagerInstance(state);
+  engine.sensorManager = ASensorManager_getInstance();
   engine.accelerometerSensor = ASensorManager_getDefaultSensor(
       engine.sensorManager, ASENSOR_TYPE_ACCELEROMETER);
   engine.sensorEventQueue = ASensorManager_createEventQueue(