Settings: Improve AOSP JA translations

They translated "hotspot" as "アクセスポイント"(access point) but it just gets us confused.
"テザリング"(Tethering) is preferred than "アクセスポイント"(access point) in Japanese translation.
FYI, most vendors fixed these strings e.g. Samsung and Sony.

Change-Id: If9aeaddc1750d1f8432fa4e1cb2e2ffb41f74b0a
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Settings into kk_mkt