[fenix] No issue: link to Configure Java guide in README; remove NDK requirement. (https://github.com/mozilla-mobile/fenix/pull/12753)

I don't have the NDK installed but I can build Fenix just fine.

README.md

@@ -67,7 +67,9 @@ Before you attempt to make a contribution please read the [Community Participati
 
 ## Build Instructions
 
-Note: Both Android SDK and NDK are required.
+Pre-requisites:
+* Android SDK
+* To run command line tools, you'll need to configure Java: see [our how-to guide](https://github.com/mozilla-mobile/shared-docs/blob/master/android/configure_java.md).
 
 1. Clone or Download the repository:
 
@@ -131,6 +133,9 @@ recommend you use our provided pre-push hook in `config/pre-push-recommended.sh`
 Using this hook will guarantee your hook gets updated as the repository changes.
 This hook tries to run as much as possible without taking too much time.
 
+Before you can run the hook, you'll need to configure Java properly because it relies on command line tools: see
+[our how-to guide](https://github.com/mozilla-mobile/shared-docs/blob/master/android/configure_java.md).
+
 To add it on Mac/Linux, run this command from the project root:
 ```sh
 ln -s ../../config/pre-push-recommended.sh .git/hooks/pre-push