Android VideoPlayer 0 size texture

It seems that Cinder on Android assumes that your videos are stored as assets. I’m trying to change the libcinder java sources similarly to @eight_io’s solution (Files cannot be read in Documents directory by Android Cinder?).

I had to change the paths in proj/android/libcinder_java/build.gradle to "${projectDir}/../../../tools/android/CinderAppBuild/repo" and /proj/android/libcinder_java/libcinder/build.gradle to "${projectDir}/../../../../src/cinder/java".
Now the project almost builds:

BUILD SUCCESSFUL

Total time: 5.307 secs

FAILURE: Build failed with an exception.

* What went wrong:
Failed to notify build listener.

I tried to update gradle, but I got an error:

* Where:
Build file '.../cinder/proj/android/libcinder_java/app/build.gradle' line: 1

* What went wrong:
A problem occurred evaluating project ':app'.
> Failed to apply plugin [id 'com.android.application']
   > Gradle version 2.2 is required. Current version is 4.4.1. If using the gradle wrapper, try editing the distributionUrl in ...cinder/proj/android/libcinder_java/gradle/wrapper/gradle-wrapper.properties to gradle-2.2-all.zip

changing this to gradle-4.4.1-all.zip results in the same error.

build tools: 28.0.3
android studio: 3.4.
ndk 15c
sdk 19 and 21

Any help or suggestions would be really appreciated.

-Gabor