enable xnnpack in default_full_aar_build_settings

[wejoncy]

Description: Describe your changes.

Motivation and Context

• Why is this change required? What problem does it solve?
• If it fixes an open issue, please link to the issue here.

[edgchen1]

Hi @Craigacp,
After enabling the XNNPACK EP in the Android package we started seeing these failures from some Android package Java tests:

ai.onnxruntime.example.javavalidator.SimpleTest > runSigmoidModelTest[ort_android(AVD) - 11] FAILED 
	java.lang.ExceptionInInitializerError
	at ai.onnxruntime.OrtEnvironment.getEnvironment(OrtEnvironment.java:81)

stack trace:
java.lang.ExceptionInInitializerError
at ai.onnxruntime.OrtEnvironment.getEnvironment(OrtEnvironment.java:81)
at ai.onnxruntime.example.javavalidator.SimpleTest.runSigmoidModelTestImpl(SimpleTest.kt:61)
at ai.onnxruntime.example.javavalidator.SimpleTest.runSigmoidModelTestImpl$default(SimpleTest.kt:57)
at ai.onnxruntime.example.javavalidator.SimpleTest.runSigmoidModelTest(SimpleTest.kt:41)
... 32 trimmed
Caused by: java.lang.IllegalArgumentException: Unknown execution provider - XnnpackExecutionProvider
at ai.onnxruntime.OrtProvider.mapFromName(OrtProvider.java:60)
at ai.onnxruntime.OnnxRuntime.initialiseProviders(OnnxRuntime.java:415)
at ai.onnxruntime.OnnxRuntime.init(OnnxRuntime.java:142)
at ai.onnxruntime.OrtEnvironment.<clinit>(OrtEnvironment.java:29)
... 37 more

Noticed this comment in the code about an unrecognized provider:

onnxruntime/java/src/main/java/ai/onnxruntime/OnnxRuntime.java

Lines 402 to 404 in 17ccd6f

	* <p>Throws IllegalArgumentException if a provider isn't recognised (note this exception should
	* only happen during development of ONNX Runtime, if it happens at any other point, file an issue
	* on Github).

What do we need to do to add support for a new EP in the Java API?

[Craigacp]

At minimum you need to add an entry to this enum

onnxruntime/java/src/main/java/ai/onnxruntime/OrtProvider.java

Line 26 in 17ccd6f

CORE_ML("CoreMLExecutionProvider");

then add whatever is necessary to turn it on in the session options.

[skottmckay]

FWIW xnnpack uses the new generic 'add ep' interface - SessionOptionsAppendExecutionProvider.

onnxruntime/include/onnxruntime/core/session/onnxruntime_c_api.h

Lines 3468 to 3472 in b83ea3c

	ORT_API2_STATUS(SessionOptionsAppendExecutionProvider, _In_ OrtSessionOptions* options,
	_In_ const char* provider_name,
	_In_reads_(num_keys) const char* const* provider_options_keys,
	_In_reads_(num_keys) const char* const* provider_options_values,
	_In_ size_t num_keys);

Can probably copy logic from existing 'add ep' implmentations, with the handling of the config key/value strings when calling the C API being similar to

onnxruntime/java/src/main/native/ai_onnxruntime_OrtSession_SessionOptions.c

Lines 348 to 358 in b83ea3c

	JNIEXPORT void JNICALL Java_ai_onnxruntime_OrtSession_00024SessionOptions_addConfigEntry
	(JNIEnv * jniEnv, jobject jobj, jlong apiHandle, jlong optionsHandle, jstring configKey, jstring configValue) {
	(void) jobj; // Required JNI parameters not needed by functions which don't need to access their host object.
	const OrtApi* api = (const OrtApi*)apiHandle;
	OrtSessionOptions* options = (OrtSessionOptions*) optionsHandle;
	const char* configKeyStr = (*jniEnv)->GetStringUTFChars(jniEnv, configKey, NULL);
	const char* configValueStr = (*jniEnv)->GetStringUTFChars(jniEnv, configValue, NULL);
	checkOrtStatus(jniEnv,api,api->AddSessionConfigEntry(options, configKeyStr, configValueStr));
	(*jniEnv)->ReleaseStringUTFChars(jniEnv, configKey, configKeyStr);
	(*jniEnv)->ReleaseStringUTFChars(jniEnv, configValue, configValueStr);
	}