Only output make targets for uninstallable static libs in the APEX
unavailable-to-platform case.

This removes the special case added in https://r.android.com/1274763
from SkipInstall(), so that it doesn't cause conflicting AndroidMk
entries when a cc_prebuilt_library_static module has prefer:true and
the corresponding source module exists.

Test: `m` in a tree with a snapshot created from art-module-sdk where
  the libartimagevalues module has prefer:true
Bug: 151303681
Change-Id: I651ae325753b707296892adb4cae80daaddb6af2
diff --git a/cc/cc.go b/cc/cc.go
index 4b36218..6f1a06d 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -418,7 +418,7 @@
 	inSanitizerDir() bool
 	hostToolPath() android.OptionalPath
 	relativeInstallPath() string
-	skipInstall(mod *Module)
+	makeUninstallable(mod *Module)
 }
 
 type xref interface {
@@ -2730,12 +2730,12 @@
 	return c.InRecovery()
 }
 
-func (c *Module) SkipInstall() {
+func (c *Module) MakeUninstallable() {
 	if c.installer == nil {
-		c.ModuleBase.SkipInstall()
+		c.ModuleBase.MakeUninstallable()
 		return
 	}
-	c.installer.skipInstall(c)
+	c.installer.makeUninstallable(c)
 }
 
 func (c *Module) HostToolPath() android.OptionalPath {