Error:Execution failed for task ':app:processDebugResources'.
com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command '/home/mobi27/opt/AND-Studio/Android/Sdk/build-tools/22.0.1/aapt'' finished with non-zero exit value 1
It appears you're missing the 22.0.1 build tools. Try going to the Tools>Android>SDK Manager and seeing what version of 'Android SDK Build-tools' you have installed. If it isn't already installed or needs an update, put a checkmark next to the 22.0.1 tools and click install.