Updated so that there are max values to the call and time thresholds
Made the app easier to share with others, and limited range of calls from 2 - 9
Modified EditTextPrompt so that an out of value range triggers an error, and modified the SettingsActivity to use the EditTextPrompt instead of a preference (MinMaxEditTextPreference), enabling the removal of the MinMaxEditTextPreference class. Refactored the code to move some constants regarding call qty and length preferences to Constants.java file.
Modified the EditTextPrompt alert when a value out of range is entered