Remove undesirable JNI lib list in makefile.

Cherrypick of ag/10846513
We were listing the JNI libraries explicitly with
LOCAL_PREBUILT_JNI_LIBS in the WebView prebuilt makefile - this hasn't
been necessary for some time, and actually causes any other .so in the
APK to be removed at build time, which is now removing the crashpad
trampoline .so and probably causing crashpad to not work correctly on
the preinstalled version as a result.

Just drop it entirely - the .so files are all preserved in the APK by
default.

Fixes: 152435891
Test: m; examine /product/app/webview/webview.apk
Change-Id: I047c0aedc4b332897a32a7f3a75a036d36b32bc1
diff --git a/Android.mk b/Android.mk
index 566b02e..cad13c6 100644
--- a/Android.mk
+++ b/Android.mk
@@ -33,9 +33,4 @@
 my_src_arch := $(call get-prebuilt-src-arch,$(LOCAL_MODULE_TARGET_ARCH))
 LOCAL_SRC_FILES := prebuilt/$(my_src_arch)/webview.apk
 
-LOCAL_PREBUILT_JNI_LIBS_arm := @lib/armeabi-v7a/libwebviewchromium.so
-LOCAL_PREBUILT_JNI_LIBS_arm64 := @lib/arm64-v8a/libwebviewchromium.so
-LOCAL_PREBUILT_JNI_LIBS_x86 := @lib/x86/libwebviewchromium.so
-LOCAL_PREBUILT_JNI_LIBS_x86_64 := @lib/x86_64/libwebviewchromium.so
-
 include $(BUILD_PREBUILT)