refactor(android): removed deprecated usage of "ndk.dir"

[jquick-axway]

JIRA:

• https://jira.appcelerator.org/browse/TIMOB-28377
• https://jira.appcelerator.org/browse/TIMOB-27801

Summary:

• Google is deprecating the ability to set the NDK folder path. They want native devs to set the NDK version instead which must be installed under Android SDK's NDK side-by-side folder.
  ./Library/Android/sdk/ndk/<version>/
• App, module, and SDK builds will no longer log the following deprecation warning
  WARNING: NDK was located by using ndk.dir property. This method is deprecated and will be removed in a future release.
• Build now uses gradle's default NDK version and will download/install it missing in Android SDK directory.
  • Now defaults to NDK version: 21.1.6352462
• Building the Titanium SDK will now auto-install NDK if not currently installed.
  • Titanium module build already support this. Was only missing for Titanium SDK builds.
• Dropped support for:
  • Environment variable: ANDROID_NDK
  • appc ti config setting: android.ndkPath

Note:
App devs can override NDK version via file: ./<app>/platform/android/build.gradle
Module devs can override NDK version via file: ./<module>/android/build.gradle

android {
	ndkVersion '21.2.6472646'
}

---

App Build Test:
Build and run any Titanium app for Android and verify it works.

Module Build Test:

1. Download the ti.imagefactory module source.
2. CD to the module's ./ti.imagefactory/android folder.
3. Build and run via: appc run -p android
4. Verify it the module builds and its example project runs in the Android emulator.

[build]

	Fails
🚫	Test suite crashed on iOS simulator. Please see the crash log for more details.

	Messages
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.
📖	✅ All tests are passing Nice one! All 11802 tests are passing. (There are 743 skipped tests not included in that total)
📖	👍 Hey!, You deleted more code than you added. That's awesome!

Generated by 🚫 dangerJS against 9348e98

[garymathews]

CR: PASS
FT: PASS

[lokeshchdhry]

FR Passed.