Introduce flat deps info list.

Compared to full list, flat list drops dependency edges and simply
lists all transitive dependencies for a top-level apex bundle.

Bug: 149622332
Test: m, manually build flatlist
Change-Id: Ibd521c96b7aeab90b95965c1b524e0a0152aaf5a
Merged-In: Ibd521c96b7aeab90b95965c1b524e0a0152aaf5a
Exempt-From-Owner-Approval: cp from aosp
(cherry picked from commit a8bd113a69)

apex/builder.go

@@ -710,6 +710,9 @@ func (a *apexBundle) buildApexDependencyInfo(ctx android.ModuleContext) {
 	ctx.Build(pctx, android.BuildParams{
 		Rule:   android.Phony,
 		Output: android.PathForPhony(ctx, a.Name()+"-deps-info"),
-		Inputs: []android.Path{a.ApexBundleDepsInfo.FullListPath()},
+		Inputs: []android.Path{
+			a.ApexBundleDepsInfo.FullListPath(),
+			a.ApexBundleDepsInfo.FlatListPath(),
+		},
 	})
 }