Fix memory flags in external services and secondary zygotes.

This change fixes a number of interconnected issues in memory safety
(MTE, GWP-ASan, nativeHeapZeroInit) runtime flags.

* Exported services use the hosting app UID to locate the process
  definition, and fail 100% of the time. Use the defining app UID and
  package name instead.
* Isolated services process name does not match the name in the defining
  app manifest, because it includes a class name and an instance number.
  Pass the defining process name in HostingRecord to address this.
* Exported service ApplicationInfo.packageName refers to the hosting
  app, again. As a result, wrong compat feature overrides are applied.
  This has been fixed before for AppZygote services; extend the fix to all
  external services.
* Pass correct memory runtimeFlags to WebViewZygote. This is important
  because both MTE and GWP-ASan have a one-way disable switch; they are
  enabled in the Zygote and disabled in the apps that do not opt-in.
  Passing 0 runtimeFlags to WebViewZygote (and AppZygote) makes it
  impossible to enable these features later in their child processes.

This change moves runtimeFlags logic from ProcessList to os.Zygote to
make it available to WebViewZygote.

Bug: 208910418
Test: CtsTaggingHostTestCases
Test: atest in frameworks/base
Test: CtsWebkitTestCases
Test: manual install WebView with android:memtagMode tag

Change-Id: I232d35344f4cd34226ff11324421904b35251525