Make jni_headers more widely available

Currently jni_headers are implicitly included by soong and require no
usage checks. Now they publicly visible and available for native_bridge
targets.

Bug: 152482542
Bug: 153609531

Test: Drop implicit include in soong && m && observe errors reduced.

Change-Id: I8cfa891ed49f4d87516936f10fced60ce2b6ae72
Merged-In: Ifc29bd154022c7f9a4527226e856be72e58e5dfc
diff --git a/Android.bp b/Android.bp
index 46f46f8..10c0ff6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -17,6 +17,7 @@
     host_supported: true,
     export_include_dirs: ["include_jni"],
     vendor_available: true,
+    native_bridge_supported: true,
     target: {
         windows: {
             enabled: true,