git: openjdk/mobile: 8231505: Bump required boot jdk version to 13

[duke]

Changeset: 634780eb
Author:    Erik Joelsson <erikj at openjdk.org>
Date:      2019-10-02 10:04:46 +0000
URL:       https://git.openjdk.java.net/mobile/commit/634780eb

8231505: Bump required boot jdk version to 13

Reviewed-by: darcy, ihse

! make/autoconf/version-numbers
! make/conf/jib-profiles.js