Drop support for legacy Space class in GridLayout.

Developers should be using platform version of Space class instead of
the androidx.legacy version. This change drop support for the legacy
version and revs the version of GridLayout to note the change.

Test: ./gradlew assembleDebug
Change-Id: I969acf9f9bf5137dbab62a05d969224045b5fe83

diff --git a/gridlayout/build.gradle b/gridlayout/build.gradle
index ddae434..c1ba369 100644
--- a/gridlayout/build.gradle
+++ b/gridlayout/build.gradle

@@ -8,7 +8,6 @@
 
 dependencies {
     api(project(":core"))
-    api(project(":legacy-support-core-ui"))
 
     androidTestImplementation(TEST_RUNNER)
     androidTestImplementation(TEST_RULES)
@@ -18,7 +17,7 @@
 supportLibrary {
     name = "Android Support Grid Layout"
     publish = true
-    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenVersion = LibraryVersions.GRIDLAYOUT
     mavenGroup = LibraryGroups.GRIDLAYOUT
     inceptionYear = "2013"
     description = "Android Support Grid Layout"