Add ARM64 architecture support

[keshayad]

Description of changes:

Add support for ARM64 architecture.

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[edhzsz]

LGTM!

[richarddd]

This does not work since the jar does not contain prebuilt libraries for both x64 and arm.
Currently:

aws-lambda-java-libs/aws-lambda-java-runtime-interface-client/src/main/java/com/amazonaws/services/lambda/runtime/api/client/runtimeapi/NativeClient.java

Lines 16 to 19 in d1b016a

	private static final String[] libsToTry = {
	"/aws-lambda-runtime-interface-client.glibc.so",
	"/aws-lambda-runtime-interface-client.musl.so",
	};

looks for only two libraries to load when https://github.com/aws/aws-lambda-java-libs/blob/master/aws-lambda-java-runtime-interface-client/src/main/jni/build-jni-lib.sh only builds for musl and gclib but not for arm

Futhermore, it would be better to build different flavours of aws-lambda-java-runtime-interface-client to accomodate the diffrent architectures and standard libraries since this code makes assumptions and relies on exception handling to load the correct library:

aws-lambda-java-libs/aws-lambda-java-runtime-interface-client/src/main/java/com/amazonaws/services/lambda/runtime/api/client/runtimeapi/NativeClient.java

Lines 23 to 39 in d1b016a

	for (int i = 0; !loaded && i < libsToTry.length; ++i) {
	try (InputStream lib = NativeClient.class.getResourceAsStream(libsToTry[i])) {
	Files.copy(lib, Paths.get(nativeLibPath), StandardCopyOption.REPLACE_EXISTING);
	System.load(nativeLibPath);
	loaded = true;
	} catch (UnsatisfiedLinkError e) {
	exceptions[i] = e;
	} catch (Exception e) {
	exceptions[i] = e;
	}
	}
	if (!loaded) {
	for (int i = 0; i < libsToTry.length; ++i) {
	System.err.printf("Failed to load the native runtime interface client library %s. Exception: %s\n", libsToTry[i], exceptions[i].getMessage());
	}
	System.exit(-1);
	}

It would be good to have:

• aws-lambda-java-runtime-interface-client-musl-x64
• aws-lambda-java-runtime-interface-client-gclib-x64
• aws-lambda-java-runtime-interface-client-musl-arm
• aws-lambda-java-runtime-interface-client-gclib-arm

Rather than one jar containing all libraries