HA Guide: Fix XML header

Do not set xml:lang and add xlink namespace.

Change-Id: I9fd243a0e2ab5c545262bf2ca3be11ee079c89e6
Imported Translations from Transifex

Change-Id: Icf3d9f5c1051e705bf7ca5516c3b605212e79f51
Merge "Imported Translations from Transifex"