ui: com.android.ProcessState explorer for android.process_state

A page (sidebar 'Process state explorer', route /process_state) for AMS
ProcessStateController snapshots, plus a timeline track so the snapshots are
visible in context.

The explorer is organised as a Winscope-style seek bar over the snapshots, an
interactive graph, and a tabbed bottom panel; the graph/panel split is
vertically draggable.

Seek bar: a tick per snapshot positioned by time, a draggable playhead, and a
quiet device-state line for the current snapshot's GlobalState (awake, top
proc-state, memory level, unlocking/shade, idle-allowlist size, and clickable
home/heavy/previous/dozing-ui pids).

Graph: an SVG process-relationship graph laying processes out in oom-adj
importance columns (left = more important), sized by binding-degree so hubs read
at a glance. Empty tiers are skipped. Service (grey) and content-provider (blue,
dashed) edges run client->server, hidden by default and revealed on hover
(light) / pinned bold on click; arrowheads inherit the edge colour. Zoom/pan via
viewBox with auto-fit until the user adjusts.

Bottom panel tabs:
  * Processes - the full process DataGrid for the snapshot.
  * <selection> - structured detail for the clicked node or edge, rendered as
    flat DataGrids: process state, how-this-adj-was-computed (the ordered
    conditions the OomAdjuster applied - adj_compute / adj_step, with a fallback
    to the most recent compute at-or-before the snapshot), hosted components,
    and inbound/outbound service & content-provider bindings (filtered to the
    current snapshot).
  * Events - a trace-wide log of the per-process lifecycle MutationEvents from
    ProcessStateController (process begin/end, oom-adj recompute, service &
    provider bind/unbind, FGS, broadcast dispatch with the intent action,
    frozen, hosting/capability/sched-group, instrumentation) with relative
    timestamps and a clickable snapshot column; uid-level and global
    device-state churn is excluded (it's already in the device-state line).

Clicking a pid anywhere drills into that process; clicking an edge shows its
binding detail (service short-names / provider authorities + connection count).

Selecting a snapshot slice on the timeline track opens a details panel with the
same graph and a horizontally-draggable graph|properties split, plus an
'Open full explorer' button that deep-links to that snapshot
(#!/process_state/<id>).

Change-Id: I42982e5e8efcce4bdc6c0b791c7365a41e474c22