Add explicit dependencies on jni_headers

Preparation for removing implicit include paths for jni.h from soong.

Also remove unnecessary jni.h includes from PathParser.{h,cpp}.

Bug: 152482542
Test: lunch aosp_x86_64 && m checkbuild
Change-Id: Ib18afa3d2c93ed3ce69204286d5177991100fd7e
Exempt-From-Owner-Approval: build refactoring
diff --git a/native/webview/loader/Android.bp b/native/webview/loader/Android.bp
index 0ba256f..dfa5bdd 100644
--- a/native/webview/loader/Android.bp
+++ b/native/webview/loader/Android.bp
@@ -24,6 +24,8 @@
 
     cflags: ["-Werror"],
 
+    header_libs: ["jni_headers"],
+
     shared_libs: [
         "libdl",
         "liblog",