android.process.media issue
The error clearly tries to write a JSON file and chokes on it. The question is now where the JSON file is located and to which app it belongs. 

My first guess would be to clear the data and cache of the system app "Media storage" (com.android.providers.media). Hopefully the JSON file belongs to this app and clearing the data resets it so that it can start again from zero size.

BTW: The "memory" here means RAM - not flash memory. Therefore clearing data/caches of unrelated apps will not help in this case.