Address verb tense discrepancy pointed out in Issue aip-dev#810 (aip-…

…dev#866)

* Update terminology from GSuite to Google Workspace

Addresses: aip-dev#818
Obsoletes: aip-dev#858

* Updated tense to match the sentence. Issue: aip-dev#810

aip/auth/4111.md

@@ -31,7 +31,7 @@ credentials][2]. To understand the overall flow, please read [AIP-4110][2].
 
 ### Scope vs. Audience
 
-In the past, the self-signed JWT is only applicable with `audience`. Recently,
+In the past, the self-signed JWT was only applicable with `audience`. Recently,
 the usage of the "scope" claim in self-signed JWTs is now allowed in the Google
 Cloud auth ecosystem, which makes the self-signed JWT usable with both audience
 and scope. However, caller **must** not specify scope and audience at the same