Leave table names with numbers untouched in DatabaseBase::generalizeSQL

The function converts numbers to general forms
Eg. 10 => N
but creates a problem for tables whose names have digits in them
Eg. l10n_cache => lNn_cache

This was fixed using regex lookarounds

Bug: 67925
Change-Id: I0e97e211f6d60ba0d639b91d3a68c5e42bfb3f78
Merge "Leave table names with numbers untouched in DatabaseBase::generalizeSQL"