Add a test for resource overlays

Add a test that checks that g_resources_get_info()
respects the G_RESOURCE_OVERLAYS environment variable.
10 jobs for resource-overlay-info in 16 minutes and 31 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build
passed #185356
cross-android_api21_arm64

00:02:01

passed #185357
cross-android_api28_arm64

00:02:00

passed #185358
cross-mingw64

00:01:17

passed #185355
fedora-autotools-x86_64

00:06:01

passed #185354
fedora-x86_64

00:04:49

passed #189816
freebsd-11
freebsd-11-x86_64

00:04:10

passed #185359
win32
msys2-mingw32

00:10:41

passed #185360
win32
vs2017-x64

00:07:58

failed #185361
freebsd-11
freebsd-11-x86_64

00:03:54

 
  Coverage
passed #185362
coverage

00:01:37

75.4%