[Build] Commit only relevant files in version increment workflow

Do not just commit every changed file in order to avoid accidental
commits of resources changed or generated during builds.
For version increments only the following files are relevant:
- META-INF/MANIFEST.MF
- feature.xml
- pom.xml

.github/workflows/checkVersions.yml

@@ -1,4 +1,4 @@
-name: Check for version increments and apply them if necessary 
+name: Check for and apply version increments
 
 on:
   workflow_call:
@@ -49,15 +49,15 @@ jobs:
     - name: Commit version increments, if any
       run: |
         set -x
-        if [[ $(git status --ignore-submodules --porcelain) != '' ]]; then
-          # Workspace is not clean, i.e. some version were changed
+        git add '*/META-INF/MANIFEST.MF' '*/feature.xml' '*/pom.xml'
+        if [[ $(git diff --name-only --cached) != '' ]]; then
+          # Relevant files were staged, i.e. some version were changed
           
           # Read 'releaseNumberSDK' property as stream version
           streamVersion=$(mvn help:evaluate -Dexpression=releaseNumberSDK --quiet -DforceStdout)
           
           git config --global user.email '${{ inputs.botMail }}'
           git config --global user.name '${{ inputs.botName }}'
-          git add --all
           git status
           git commit -m "Version bump(s) for ${streamVersion} stream"