cmake 3.10 (which comes with Ubuntu 18.04) in combination with Qt 5.12
and the current qt-android-cmake causes an odd bug. Paths are set with a
double slash at the start '//' and later in the process this causes
garbled path names for some of the objects which in return causes the
APKs built in the container to fail.
Upgrading the cmake inside the container to 3.13.2 fixes that problem.
All the credit for identifying the problem and figuring out a solution
goes to Jan Mulder.
The resulting container was pushed to Docker hub as version to 5.12.03.
Reported-by: Jan Mulder <jlmulder@xs4all.nl>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
As explained in commit 449d4ee33d ("Android build: add explanation for
huge hack").
It seems reasonable to add this to our Travis image as that is custom
made just to build our Android binaries.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
