Updates Gradle Wrapper from 6.2.1 to 6.7

[github-actions]

Updates Gradle Wrapper from 6.2.1 to 6.7.

See release notes: https://docs.gradle.org/6.7/release-notes.html

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🤖 This PR has been created by the Update Gradle Wrapper action.

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❌ fdoxyz
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[fdocr]

Android Studio seems to have a problem if distributionSha256Sum is available within the gradle-wrapper.properties so I manually removed it.

Tried it out locally and the bump LGTM

[maestromac]

Awesome job @fdoxyz ! It's working for me too