[NAN] Update API: replace looper with handler

Per API council guidelines.

(cherry-pick of commit ff855f6b0c7011937117ce0af4e8098be8af28f9)

Bug: 31377060
Test: unit tests, integrated (sl4a) tests
Change-Id: I557d5bcce668e03d95a86b9f394b72a87718051a
2 files changed
tree: cb2fab7abb682f43e85eaebceec281bdf2c52bb9
  1. service/