Revert "Tweak detection of Bamboo (#23597)"

This reverts commit 35567678ef, reversing
changes made to 807e1d3367.

gradle/build-scan-user-data.gradle

@@ -44,17 +44,13 @@ void addGitMetadata() {
 
 void addCiMetadata() {
 	def ciBuild = 'CI BUILD'
-	if (isBamboo()) {
-		buildScan.link ciBuild, System.getenv('bamboo_resultsUrl')
+	if (System.getenv('bamboo.resultsUrl')) {
+		buildScan.link ciBuild, System.getenv('bamboo.resultsUrl')
 	}
 }
 
 boolean isCi() {
-	isBamboo()
-}
-
-boolean isBamboo() {
-	System.getenv('bamboo_resultsUrl')
+	System.getenv('bamboo.resultsUrl')
 }
 
 String execAndGetStdout(String... args) {