Enable LTO for Android build

[snnn]

Description

Enable LTO for Android build, which can reduce binary size by 6%.

Motivation and Context

[edgchen1]

should we also enable this in a build that gets tested more? e.g., the actual package builds that will be published and CI builds.

[snnn]

should we also enable this in a build that gets tested more? e.g., the actual package builds that will be published and CI builds.

Where should I modify?

[edgchen1]

should we also enable this in a build that gets tested more? e.g., the actual package builds that will be published and CI builds.

Where should I modify?

package build settings are here:

onnxruntime/tools/ci_build/github/android/default_full_aar_build_settings.json

Lines 10 to 19 in f39ee14

	"build_params": [
	"--android",
	"--parallel",
	"--cmake_generator=Ninja",
	"--build_java",
	"--build_shared_lib",
	"--use_nnapi",
	"--use_xnnpack",
	"--skip_tests"
	]

onnxruntime/tools/ci_build/github/android/training_full_aar_build_settings.json

Lines 10 to 20 in f39ee14

	"build_params": [
	"--android",
	"--parallel",
	"--cmake_generator=Ninja",
	"--build_java",
	"--build_shared_lib",
	"--use_nnapi",
	"--use_xnnpack",
	"--skip_tests",
	"--enable_training_apis"
	]

CI build is here:
https://github.com/microsoft/onnxruntime/blob/main/tools/ci_build/github/azure-pipelines/android-x86_64-crosscompile-ci-pipeline.yml