[native] Fix Android CI

Summary:
Android Buildkite CI is consistently showing this error now (example):

Unrecognized VM option 'MaxPermSize=4096m'

Apparently this option has been deprecated.

This option was removed in the React Native template's gradle.properties starting in 0.69, but I neglected to remove it during my most recent upgrade since I assumed our customization should be kept based on the contents of 24dd5bd2b9de7ffff06db6aa0d755ebfcc2730d4.

Given that the option is now causing CI to fail, and given that the template's config seems to include an updated heap size now, I figure we can realign our gradle.properties back to match what is in the React Native template.

Test Plan: See if this diff passes Buildkite CI

Reviewers: atul, jon, bartek, tomek

Reviewed By: atul

Differential Revision: https://phab.comm.dev/D7578