Switch openSUSE to 42.3 by default

This is the latest stable release, so we should default to it.

Change-Id: I05643787002d339ccbf7a718847fe4ed6f39eacc

diskimage_builder/elements/opensuse-minimal/README.rst

@@ -13,5 +13,5 @@ Environment Variables
 
 DIB_RELEASE
   :Required: No
-  :Default: 42.2
+  :Default: 42.3
   :Description: Set the desired openSUSE release.

diskimage_builder/elements/opensuse-minimal/environment.d/10-opensuse-distro-name.bash

@@ -1,4 +1,4 @@
 export DISTRO_NAME=opensuse
-DIB_RELEASE=${DIB_RELEASE:-42.2}
+DIB_RELEASE=${DIB_RELEASE:-42.3}
 export DIB_RELEASE=${DIB_RELEASE,,}
 export DIB_OPENSUSE_PATTERNS=patterns-openSUSE-base

diskimage_builder/elements/opensuse/README.rst

@@ -14,7 +14,7 @@ Environment Variables
 
 DIB_RELEASE
   :Required: No
-  :Default: 42.2
+  :Default: 42.3
   :Description: Set the desired openSUSE release.
 
 DIB_CLOUD_IMAGES

diskimage_builder/elements/opensuse/environment.d/10-opensuse-distro-name.bash

@@ -1,5 +1,5 @@
 export DISTRO_NAME=opensuse
-export DIB_RELEASE=${DIB_RELEASE:-42.2}
+export DIB_RELEASE=${DIB_RELEASE:-42.3}
 export DIB_OPENSUSE_PATTERNS=patterns-openSUSE-base
 case ${DIB_RELEASE} in
     # Old openSUSE releases

releasenotes/notes/opensuse-423-default-3bc73fff69374cd0.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    The opensuse and opensuse-minimal element are now defaulting to 42.3, which
+    is the latest stable openSUSE release. Building for 42.2 is still supported,
+    however requires setting DIB_RELEASE to '42.2' explicitly.