Revert "Temporarily revert the SELinux policy for persist.netd.stable_secret."

This change must only be submitted when device-specific policies
have been reverted.

This reverts commit 07e631d2.

Bug: 17613910
Test: builds
Change-Id: Ie33e293107bf1eba2498f2422d941544c76b8cad
Merged-In: I356c39a5dc955b3d7c28d8c7baf2887a17beb272