Renaming useMaxDepVersions -> androidx.useMaxDepVersions

1. to clarify what interprets it
2. to more easily validate that it is spelled correctly
3. it also gets added to the list of known androidx.* properties in case of a spelling error

Bug: 167399374
Test: ./gradlew :buildSrc-tests:build -Pandroidx.useMaxDepVersions
Test: Treehugger runs busytown/*.sh

Change-Id: Ie13e29c12a80a3558d8b77becacabf3d4bde6269
diff --git a/settings.gradle b/settings.gradle
index cae4b3a..d90adf4a 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -163,8 +163,8 @@
 includeProject(":biometric:integration-tests:testapp", "biometric/integration-tests/testapp", [BuildType.MAIN])
 includeProject(":browser:browser", "browser/browser", [BuildType.MAIN])
 includeProject(":buildSrc-tests", "buildSrc-tests", [BuildType.MAIN])
-// these projects intentionally fail to compile unless useMaxDepVersions is enabled
-if (startParameter.projectProperties.containsKey('useMaxDepVersions')) {
+// these projects intentionally fail to compile unless androidx.useMaxDepVersions is enabled
+if (startParameter.projectProperties.containsKey('androidx.useMaxDepVersions')) {
     includeProject(":buildSrc-tests:max-dep-versions:buildSrc-tests-max-dep-versions-dep", "buildSrc-tests/max-dep-versions/buildSrc-tests-max-dep-versions-dep", [BuildType.MAIN])
     includeProject(":buildSrc-tests:max-dep-versions:buildSrc-tests-max-dep-versions-main", "buildSrc-tests/max-dep-versions/buildSrc-tests-max-dep-versions-main", [BuildType.MAIN])
 }