[8.9] Adjust global loading indicator data-test-subj for projects (#163697) (#163745)

# Backport

This will backport the following commits from `main` to `8.9`:
- [Adjust global loading indicator data-test-subj for projects
(#163697)](https://github.com/elastic/kibana/pull/163697)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Robert
Oskamp","email":"robert.oskamp@elastic.co"},"sourceCommit":{"committedDate":"2023-08-11T17:40:26Z","message":"Adjust
global loading indicator data-test-subj for projects (#163697)\n\n##
Summary\r\n\r\nThis PR adjusts the `data-test-subj` for the global
loading indicator in\r\nserverless projects such that at matches the
stateful version. This\r\nmakes sure that functional tests and
corresponding test helper methods\r\ncontinue to work the same in
stateful and serverless environments when\r\ncomes to waiting for global
loading to finish, which is a key mechanism\r\nto avoid test
flakiness.\r\n\r\n### Additional information\r\n\r\n- The serverless
project specific global loading indicator was\r\nintroduced with
#158523\r\n- The stateful loading indicator `data-test-subj` naming is
implemented\r\nhere:\r\nhttps://github.com/elastic/kibana/blob/main/packages/core/chrome/core-chrome-browser-internal/src/ui/loading_indicator.tsx#L61\r\n\r\nCo-authored-by:
Tim Sullivan
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global loading indicator data-test-subj for projects (#163697)\n\n##
Summary\r\n\r\nThis PR adjusts the `data-test-subj` for the global
loading indicator in\r\nserverless projects such that at matches the
stateful version. This\r\nmakes sure that functional tests and
corresponding test helper methods\r\ncontinue to work the same in
stateful and serverless environments when\r\ncomes to waiting for global
loading to finish, which is a key mechanism\r\nto avoid test
flakiness.\r\n\r\n### Additional information\r\n\r\n- The serverless
project specific global loading indicator was\r\nintroduced with
#158523\r\n- The stateful loading indicator `data-test-subj` naming is
implemented\r\nhere:\r\nhttps://github.com/elastic/kibana/blob/main/packages/core/chrome/core-chrome-browser-internal/src/ui/loading_indicator.tsx#L61\r\n\r\nCo-authored-by:
Tim Sullivan
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global loading indicator data-test-subj for projects (#163697)\n\n##
Summary\r\n\r\nThis PR adjusts the `data-test-subj` for the global
loading indicator in\r\nserverless projects such that at matches the
stateful version. This\r\nmakes sure that functional tests and
corresponding test helper methods\r\ncontinue to work the same in
stateful and serverless environments when\r\ncomes to waiting for global
loading to finish, which is a key mechanism\r\nto avoid test
flakiness.\r\n\r\n### Additional information\r\n\r\n- The serverless
project specific global loading indicator was\r\nintroduced with
#158523\r\n- The stateful loading indicator `data-test-subj` naming is
implemented\r\nhere:\r\nhttps://github.com/elastic/kibana/blob/main/packages/core/chrome/core-chrome-browser-internal/src/ui/loading_indicator.tsx#L61\r\n\r\nCo-authored-by:
Tim Sullivan
<tsullivan@users.noreply.github.com>","sha":"fd08c62f052d065e677b670a381840ae80dc9724"}},{"branch":"8.9","label":"v8.9.1","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"}]}]
BACKPORT-->

Co-authored-by: Robert Oskamp <robert.oskamp@elastic.co>

packages/core/chrome/core-chrome-browser-internal/src/ui/project/header.tsx

@@ -132,14 +132,14 @@ const Logo = (
   );
 
   return (
-    <span css={logo.container}>
+    <span css={logo.container} data-test-subj="nav-header-logo">
       {loadingCount === 0 ? (
         <EuiHeaderLogo
           iconType="logoElastic"
           onClick={navigateHome}
           href={fullHref}
           css={logo}
-          data-test-subj="nav-header-logo"
+          data-test-subj="globalLoadingIndicator-hidden"
           aria-label={headerStrings.logo.ariaLabel}
         />
       ) : (
@@ -148,7 +148,7 @@ const Logo = (
             size="l"
             aria-hidden={false}
             onClick={navigateHome}
-            data-test-subj="nav-header-loading-spinner"
+            data-test-subj="globalLoadingIndicator"
           />
         </a>
       )}