Move checking of minApiForArch for apex into cc

I49220cbec628f1508709741dc56b62aaac7786d9 attempted to allow
apexes to depend on native code whose min_sdk_version had been
increased to meet the minimum supported API level for a new
architecture.  It wasn't quite right, as it assumed that the
primary architecture of the apex would be the newest, and
it applied to all dependencies, not just ones that were
specfiic to the new architecture.  Move the checking into
cc.ShouldSupportSdkVersion, where it can be specific to an
individual architecture variant.

Bug: 250918230
Test: TestApexMinSdkVersion_MinApiForArch
Change-Id: I303cf485ba54b4c6bf63a9f9b49286ff9b2c9c83
diff --git a/cc/api_level.go b/cc/api_level.go
index 8f9e1f6..fdff5cb 100644
--- a/cc/api_level.go
+++ b/cc/api_level.go
@@ -20,7 +20,7 @@
 	"android/soong/android"
 )
 
-func MinApiForArch(ctx android.EarlyModuleContext,
+func minApiForArch(ctx android.EarlyModuleContext,
 	arch android.ArchType) android.ApiLevel {
 
 	switch arch {
@@ -38,7 +38,7 @@
 func nativeApiLevelFromUser(ctx android.BaseModuleContext,
 	raw string) (android.ApiLevel, error) {
 
-	min := MinApiForArch(ctx, ctx.Arch().ArchType)
+	min := minApiForArch(ctx, ctx.Arch().ArchType)
 	if raw == "minimum" {
 		return min, nil
 	}