This follows up to a recent CL [1] that removed #getPrimary() method
from LocaleList class.

 [1] I75f77aea6b75e38793ed8477e5e5a4420d5e6d85
     fee44846376c212114223fc4259382921e6dca7a

Bug: 26984092
Change-Id: Ied4678d35c4dcb380ce24e9bce9336dbbf6c16b8

This CL updates LatinIME's compatibility library so that we can access
EditorInfo#hintLocales without directly depending on unreleased SDK.

Bug: 22859862
Change-Id: I4ba7d294bc314002c3abf8842f097a4249783364

Multi-project commit with I249d5fbe

Change-Id: Ia28c4e970992aa1299a30e604eaa5d096655c3a5

Change-Id: Ic4f69b4c8da33c9fca50d6829724179310c2f875

Bug: 6129704
Change-Id: I52925ae7bd80683f63efc48649448865a5654f41

Bug: 6129704
Change-Id: I5b9964f2ad52e7cd60c63acca93d0241a1e729ef

Bug: 6037537
Bug: 5961814
Change-Id: I9c6dedf953452a180fcd5bce7bfadfd3c821f224

This change also
 * Honors the custom action label in EditorInfo.actionLabel.
 * Invokes InputConnection.performeEditorAction if action is specifed
   at EditorInfo.imeOptions or actionLabel/actionId.
 * Stops using InputMethodService.sendKeyChar. Implements
   sendKeyCodePoint instead.

Bug: 2498607
Bug: 5961809
Bug: 5368408
Change-Id: If4cd5eb3dacfc6b6a7ea434b0617c2438e06e42d

Bug: 5850605
Change-Id: I6665b483f775094903f2e26f5584e4b141592ab5

This is a cherry-pick cheof I190a71f7 from Master.

Bug: 5315001
Change-Id: I76c756eeecf21eec4c88dd4558d5c50f10ff3d3c

This change also separates controlling visibility of "key preview
backing view" from suggestions strip visibility.

Bug: 5315001
Change-Id: I190a71f7956c804e5d89d2d5bacecc62d565ac2c

Bug: 5030408
Change-Id: I1c5649725780cd063db7a437b8559b7f2573469c

Previously tab key is shown only when the input type variant says that
it is web input.  In addition to that, this change also shows tab key
when the IME option includes editor action (next and/or previous)
flag.

Bug: 3094312
Change-Id: I3f8841fdbcee918a0f93f3259090f24e70d96471

Change-Id: I377042c1750dd97b922bcf40bffb4046e023f6bb

- imeOptionName

Change-Id: I7a7ea9bee410cedc0ef9b3d2aa4df8260d7f6a35

Change-Id: Ie69d5e90c4ee978d3ecb40b68e6466082569ca7a