Revert "Add a11y focus on battery chart a11y node."

This reverts commit 1d134d66.

Reason for revert: <Potential culprit for b/342336993  - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.>

Change-Id: Ifa208bbc77fc4f49b6465fd68d9a18e31d1d3254