Set translatable=false

These kind of values shouldn't be controlled by the translation.

Preferably, this shouldn't need an _entries array at all, but instead
strings for "minutes" and "Inifinite".
Maybe even a string format for any language that might put the string
before the number?

Change-Id: Id057c6f5eb004e5b0c2adc82c79be037196d46e0