WifiNetworkSpecifier/Suggestion: Address API council comments

Modified builder methods to:
a) Add boolean input for all boolean setters.
b) Add a public value for unassigned priority and added IntRange
annotation.

Bug: 128317241
Bug: 128317186
Test: Compiles
Test: ./frameworks/base/wifi/tests/runtest.sh
Change-Id: Iaf9d26ed857fe9337d3e4006c9c894efbcfa32dd