Remove "exported" ninja variables

There was infrastructure to export ninja variables to bazel. Now that
the bazel migration is cancelled, we don't need it anymore.

Bug: 315353489
Test: m nothing
Change-Id: I298cc2ac7ebd004557be3b30d75f7357cab0b7a0
diff --git a/cc/config/arm64_linux_host.go b/cc/config/arm64_linux_host.go
index f7d190b..438e0e6 100644
--- a/cc/config/arm64_linux_host.go
+++ b/cc/config/arm64_linux_host.go
@@ -61,9 +61,9 @@
 )
 
 func init() {
-	exportedVars.ExportStringListStaticVariable("LinuxBionicArm64Cflags", linuxCrossCflags)
-	exportedVars.ExportStringListStaticVariable("LinuxBionicArm64Ldflags", linuxCrossLdflags)
-	exportedVars.ExportStringListStaticVariable("LinuxBionicArm64Lldflags", linuxCrossLldflags)
+	pctx.StaticVariable("LinuxBionicArm64Cflags", strings.Join(linuxCrossCflags, " "))
+	pctx.StaticVariable("LinuxBionicArm64Ldflags", strings.Join(linuxCrossLdflags, " "))
+	pctx.StaticVariable("LinuxBionicArm64Lldflags", strings.Join(linuxCrossLldflags, " "))
 }
 
 // toolchain config for ARM64 Linux CrossHost. Almost everything is the same as the ARM64 Android