Don't show animation on dialog close.

After UX consultation it was concluded that the exit animation should be
prevented.

Flag: LEGACY ENABLE_NEW_PRIVACY_DIALOG ENABLED
Test: atest SystemUITests:com.android.systemui.privacy.PrivacyDialogControllerV2Test
Test: manually tested as well
Bug: 306168530
Change-Id: I33eabfa6e0a0ba090d4342f2305e1d8fe6e02c04