[4.5.x] APIM 7527: fix handle null values for total api's in category mapping

[mergify]

This is an automatic copy of pull request #9953 done by Mergify.

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Issue

https://gravitee.atlassian.net/browse/APIM-7527

Description

Used getOrDeafult to handle null value in total apis in category mapping.

Additional context

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Cherry-pick of c45d68e has failed:

On branch mergify/bp/4.5.x/pr-9953
Your branch is up to date with 'origin/4.5.x'.

You are currently cherry-picking commit c45d68edcc.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   gravitee-apim-rest-api/gravitee-apim-rest-api-portal/gravitee-apim-rest-api-portal-rest/src/main/java/io/gravitee/rest/api/portal/rest/resource/ApisResource.java
	both modified:   gravitee-apim-rest-api/gravitee-apim-rest-api-portal/gravitee-apim-rest-api-portal-rest/src/test/java/io/gravitee/rest/api/portal/rest/resource/ApisResourceTest.java

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[mergify]

Cherry-pick of c45d68e has failed:

On branch mergify/bp/4.5.x/pr-9953
Your branch is up to date with 'origin/4.5.x'.

You are currently cherry-picking commit c45d68edcc.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   gravitee-apim-rest-api/gravitee-apim-rest-api-portal/gravitee-apim-rest-api-portal-rest/src/main/java/io/gravitee/rest/api/portal/rest/resource/ApisResource.java
	both modified:   gravitee-apim-rest-api/gravitee-apim-rest-api-portal/gravitee-apim-rest-api-portal-rest/src/test/java/io/gravitee/rest/api/portal/rest/resource/ApisResourceTest.java

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[mukul-tyagi08]

Issue already fixed on 4.5: https://gravitee.atlassian.net/browse/APIM-7299