Make Bionic and kernel system includes explicit in the blueprints.

Before this Soong added hardcoded system include paths to
bionic/libc/{include,kernel}, which won't work when Bionic libs are
packaged up as prebuilts in an SDK module snapshot.

Test: Build and boot
Test: Check in out/verbose.log.gz that a C file doesn't get any bionic
  include path for linux_glibc.
Bug: 153590472
Change-Id: I13c8eb3dd7150d6e0fee001b290b53fcebebcfea
diff --git a/libdl/Android.bp b/libdl/Android.bp
index 8e3a3fc..37bdbdd 100644
--- a/libdl/Android.bp
+++ b/libdl/Android.bp
@@ -25,6 +25,7 @@
 
     stl: "none",
     system_shared_libs: [],
+    header_libs: ["libc_headers"],
 
     sanitize: {
         never: true,
@@ -97,6 +98,7 @@
 
     nocrt: true,
     system_shared_libs: [],
+    header_libs: ["libc_headers"],
 
     // Opt out of native_coverage when opting out of system_shared_libs
     native_coverage: false,
@@ -175,6 +177,7 @@
 
     nocrt: true,
     system_shared_libs: [],
+    header_libs: ["libc_headers"],
 
     // Opt out of native_coverage when opting out of system_shared_libs
     native_coverage: false,