Revert "Add the slider widget to SPA and create samples in codelab slider page."

This reverts commit 56a73e38.

Reason for revert: DroidMonitor: Potential culprit for Bug b/242475159 - 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: Icbf40268213dfb3132f3417208e033361674fa16