Relocate KeepalivePacketData to frameworks/base

Due to an issue resolving the boot classpath, the
KeepalivePacketData structure cannot be referenced
by frameworks/opt/telephony while it is in services;

Update references in wifi to point to the new package
name, android.net.

Bug: 38350389
Test: compilation
Merged-In: I620933b6d5bbf0177c4dda9e2f4933e5c2a63310
Change-Id: I620933b6d5bbf0177c4dda9e2f4933e5c2a63310
(cherry picked from commit 505663e1f5ecfd9ec588f5d9073915a5f0a9ecc1)
4 files changed