Remove libc_headers from cc_object

cc_object modules get default libraries like libc now and no longer
need to explicitly include libc_headers.

Bug: 153662223
Test: m libminijail_gen_syscall_obj libminijail_gen_constants_obj libminijail_gen_constants_llvmir libminijail_gen_syscall_llvmir
Change-Id: I5381dd2d2ae57e259c140b0e21c776355192de67
diff --git a/Android.bp b/Android.bp
index c8cbd89..9cb6b0c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -91,7 +91,6 @@
     vendor_available: true,
     product_available: true,
     recovery_available: true,
-    header_libs: ["libc_headers"], // TODO(b/153662223): Clean this up.
     srcs: ["gen_syscalls.c"],
     cflags: [
         "-dD",
@@ -132,7 +131,6 @@
     vendor_available: true,
     product_available: true,
     recovery_available: true,
-    header_libs: ["libc_headers"], // TODO(b/153662223): Clean this up.
     srcs: ["gen_constants.c"],
     cflags: [
         "-dD",
@@ -206,7 +204,6 @@
     product_available: true,
     recovery_available: true,
     host_supported: true,
-    header_libs: ["libc_headers"], // TODO(b/153662223): Clean this up.
     cflags: [
         "-S",
         "-O0",
@@ -229,7 +226,6 @@
     product_available: true,
     recovery_available: true,
     host_supported: true,
-    header_libs: ["libc_headers"], // TODO(b/153662223): Clean this up.
     cflags: [
         "-S",
         "-O0",