Convert CheckMinSdkVersion to use providers.

Next step is to convert it to use ModuleProxy once IsDepInSameApex is
converted to use providers.

Bug: 377723687
Test: Unit tests and compare the ninja and mk files generated.
Change-Id: I20cb052666fa95eb964e63e3302ac892d3324183
diff --git a/android/api_levels.go b/android/api_levels.go
index b4fa251..6d0c389 100644
--- a/android/api_levels.go
+++ b/android/api_levels.go
@@ -252,6 +252,9 @@
 	isPreview: true,
 }
 
+// A special ApiLevel that all modules should at least support.
+var MinApiLevel = ApiLevel{number: 1}
+
 // Sentinel ApiLevel to validate that an apiLevel is either an int or a recognized codename.
 var InvalidApiLevel = NewInvalidApiLevel("invalid")