[Telemetry SWX] Rename GetAvailableRoutines test

Rename GetAvailableRoutines test to comply with other diagnostics
tests.

Bug: b:168793232
Change-Id: I9e18b091859c1b711ab0f528c901a964c3771888
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416493
Commit-Queue: Laurențiu Olteanu <lolteanu@google.com>
Reviewed-by: Mahmoud Gawad <mgawad@google.com>
Reviewed-by: Oleh Lamzin <lamzin@google.com>
Cr-Commit-Position: refs/heads/master@{#808790}

chromeos/components/telemetry_extension_ui/test/telemetry_extension_ui_browsertest.js

@@ -375,7 +375,7 @@ var TelemetryExtensionUIWithProbeServiceErrorsBrowserTest =
 // Example: ['UntrustedAwesomeTest', 'MyAwesomeTestClass']
 const untrustedTests = [
   ['UntrustedCanSpawnWorkers'],
-  ['UntrustedRequestAvailableRoutines'],
+  ['UntrustedDiagnosticsRequestAvailableRoutines'],
   ['UntrustedDiagnosticsRequestRoutineUpdateUnknownArguments'],
   ['UntrustedDiagnosticsRequestRunBatteryCapacityRoutine'],
   ['UntrustedDiagnosticsRequestRunBatteryHealthRoutine'],

chromeos/components/telemetry_extension_ui/test/untrusted_browsertest.js

@@ -52,7 +52,7 @@ UNTRUSTED_TEST('UntrustedCanSpawnWorkers', async () => {
 
 // Tests that array of available routines can be successfully
 // requested from chrome-untrusted://.
-UNTRUSTED_TEST('UntrustedRequestAvailableRoutines', async () => {
+UNTRUSTED_TEST('UntrustedDiagnosticsRequestAvailableRoutines', async () => {
   const response = await chromeos.diagnostics.getAvailableRoutines();
   assertDeepEquals(response, [
     'battery-capacity',