[DPP] Rename "DPP" public API to "Easy Connect"

Rename all DPP public API and constants to use Easy Connect naming,
whic is the WFA public technology name

Bug: 122851551
Test: atest DppManagerTest
Test: act.py -c ../WifiDppConfig.json -tc WifiDppTest
Change-Id: Iaf30b62d8981b55e07cb509a4f12a476baf22768
4 files changed