Updated the libwebp with version 0.4.0-rc1

Updated the libwebp with the release 0.4.0-rc1 (change#I22be12d8).

Build & Ran following tests for Nexus N7 (Razor)
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/BitmapTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/BitmapFactoryTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/BitmapRegionDecoderTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/Bitmap_CompressFormatTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/Bitmap_ConfigTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/BitmapFactory_OptionsTest.java
runtest --path cts/tests/tests/graphics/src/android/graphics/cts/BitmapShaderTest.java

Also did the full Android build for following targets:
- flo
- grouper
- mako
- x86

Before this change is submitted, need to submit the change for cts/tests to update the threshold for WebP encoding for color-mode RGB565.
(Refer: https://googleplex-android-review.git.corp.google.com/#/c/403360/)

Change-Id: Ib2db2ebf0395276d45c3e8dc70d7b451e3678e6f
90 files changed