Make binaries executable

Split InstallFileName into InstallExecutable that does chmod +x
after copying the file.  Also remove InstallFile and rename
InstallFileName to InstallFile.

Test: m -j checkbuild
Change-Id: Id41ad4eafe521f6cd5d8cc250b7747ecb3da8dfc
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index 089ce28..9fca053 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -125,7 +125,7 @@
 		outputFile := android.PathForModuleOut(ctx, fileName)
 
 		ctx.ModuleBuild(pctx, android.ModuleBuildParams{
-			Rule:        android.Cp,
+			Rule:        android.CpExecutable,
 			Description: "prebuilt",
 			Output:      outputFile,
 			Input:       p.Prebuilt.SingleSourcePath(ctx),