Clean up min_sdk_version allowlist

Hard-coded min_sdk_version is not necessary for kotlinx-* modules
because they are already marked by updater script.

Bug: 158059172
Test: m nothing
Change-Id: I42cf26c9390244f93059af68027cca4f8518a828
diff --git a/android/apex.go b/android/apex.go
index b127f74..030fbdc 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -870,10 +870,6 @@
 	"gemmlowp_headers":                                         30,
 	"guava-listenablefuture-prebuilt-jar":                      30,
 	"ike-internals":                                            30,
-	"kotlinx-coroutines-android":                               28,
-	"kotlinx-coroutines-android-nodeps":                        30,
-	"kotlinx-coroutines-core":                                  28,
-	"kotlinx-coroutines-core-nodeps":                           30,
 	"libbrotli":                                                30,
 	"libcrypto_static":                                         30,
 	"libeigen":                                                 30,