Update Chromium-based WebView to version 70.0.3538.27

This replaces AOSP WebView by a version built from the Chromium source
tree. AOSP WebView is not supported anymore and using the Chromium
sources instead is the officially proposed way to receive WebView
updates on non-GMS builds.

GN configuration:
    target_os="android"
    is_debug=false
    symbol_level=0
    remove_webcore_debug_symbols=true
    enable_nacl=false
    ffmpeg_branding="Chrome"
    proprietary_codecs=true

Issue: FP2N-315
Change-Id: Ieaae295426ff096b51ce17ba79f22f848391e8a1
diff --git a/Android.mk b/Android.mk
index 811af65..db029bf 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1,5 +1,6 @@
 #
 # Copyright (C) 2014 The Android Open Source Project
+# Copyright 2018 Fairphone B.V.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -28,14 +29,9 @@
         libwebviewchromium_loader \
         libwebviewchromium_plat_support
 
-LOCAL_MODULE_TARGET_ARCH := arm arm64 mips x86 x86_64
-my_src_arch := $(call get-prebuilt-src-arch,$(LOCAL_MODULE_TARGET_ARCH))
-LOCAL_SRC_FILES := prebuilt/$(my_src_arch)/webview.apk
+LOCAL_MODULE_TARGET_ARCH := arm
+LOCAL_SRC_FILES := prebuilt/arm/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_mips := @lib/mips/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)