liblog: move android_log_event_context class to log/log_event_list.h

rename class from android_log_event_context to android_log_event_list

Test: gTest logcat-unit-tests
Bug: 31992412
Bug: 31456426
Change-Id: Ib61cbca7d453837d64959c56b0e11f8c5edbfbdd
7 files changed