[GH] Trigger the workflows on push.
[GH] Trigger the workflows on push.

* This will ensure that we catch breakages faster.
* `push`  ensures that pushes to `androidx-master-dev` builds everytime copybara merges commits. If they fail at least we when.

Test: Workflows.

This is an imported pull request from https://github.com/androidx/androidx/pull/51.

Resolves #51
Github-Pr-Head-Sha: 040fdc9c9c944b891979367e4306f007214a08d8
GitOrigin-RevId: 303e7c21f014e7565304c9df2b9e336f25e78303
Change-Id: I3ed856fddc3b0ce6cdb5e5b1cc3fa9de3ec8872d

androidx/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,androidx/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,AndroidX/androidx,androidx/androidx,AndroidX/androidx,androidx/androidx,androidx/androidx,AndroidX/androidx