Inline/remove unnecessary instance fields from PM.

Following the recommendations from go/tott/343. Many of these fields are
assigned in the constructor and never read afterwards.

In some cases, they weren't ever read, so I removed them altogether
(assuming their construction yields no side-effects).

Bug: 274764512
Test: "m dist" and started cuttlefish instance.
Change-Id: I6c2e96ce1b8e29ba700b334f9f32d3b1b5dbfbdd