docs: remove obsolete FAQ pages

These pages have not been maintained and have not been included in the
DAC navigation structure for some time.

b/19413080

redirects change: If512bdf55b16f0faf21de7db81ab26d59489da15

Change-Id: Ibc1aa5c691edb938cbb7d4b2d885f1ea8a5f6ef4
6 files changed