DO NOT MERGE

- Captures complete motion data for all words in an n-gram.
- Also filters n-grams properly; if any word in the n-gram is not
  in the dictionary, it is not included.
- Simplify ResearchLog to not require explicit state
- Added LogBuffer class MainLogBuffer class to allow n-gram-level decisions
  about privacy.
- Moved LogUnit out from ResearchLogger

multi-project change with Ie2bc79fd7fe6b951b24771e94b8d4ca21989af65

Bug: 6188932
Change-Id: I568c90d4af07e7c759c1e7fc64b716bd8c7b4ae5

- new package: com.android.inputmethod.research

multi-project commit with Ic0a5744f3160d13218addd589890623c0d120ffc

Bug: 6188932

Change-Id: Icf8d4a40a5725401799be6e209a640d99a5f34c4

Bug: 6188932
Change-Id: I692e427ba2e6da7bb15f48208304c4a034392a22

- separate ResearchLog from ResearchLogger
- fix abort menu to explicitly indicate re-enabling of logging
- auto flush entries every 5s
- conform to new suggestedWords class

multi-project change with I9fe1f8fe59d5891daa4ca84af157f36fb1bb17dc

Bug: 6188932

Change-Id: I7e99390f934481c6ed9cea2b259944583edda5bb