DynamicSystemInstallationService: Support remount for DSU guest system

DSU service would try to install a DSU scratch partition if host system
is debuggable.
If the scratch partition failed to install, then skip installing
scratch, as remount support should be optional.
Otherwise if the guest system is non-debuggable, then the scratch
partition would be ignored by guest, which is harmless.
Otherwise the guest system is debuggable, which means the guest system
would be able to do adb remount.

Relax partition allocation status polling rate from 10ms -> 100ms,
because there's no point polling faster than the screen framerate.

Bug: 165925766
Test: TH
Test: Install a DSU system on a debuggable host, reboot into the guest
  system, and guest system can remount.
Change-Id: I9a8255483cc963ebcf7a2909e68ac69371cb369f

2 files changed, 17 insertions, 0 deletions

diff --git a/core/java/android/os/image/DynamicSystemManager.java b/core/java/android/os/image/DynamicSystemManager.java
index 7f01cad940ec..e8e47857ecba 100644
--- a/core/java/android/os/image/DynamicSystemManager.java
+++ b/core/java/android/os/image/DynamicSystemManager.java
@@ -269,4 +269,16 @@ public class DynamicSystemManager {
             throw new RuntimeException(e.toString());
         }
     }
+
+    /**
+     * Returns the suggested scratch partition size for overlayFS.
+     */
+    @RequiresPermission(android.Manifest.permission.MANAGE_DYNAMIC_SYSTEM)
+    public long suggestScratchSize() {
+        try {
+            return mService.suggestScratchSize();
+        } catch (RemoteException e) {
+            throw new RuntimeException(e.toString());
+        }
+    }
 }
diff --git a/core/java/android/os/image/IDynamicSystemService.aidl b/core/java/android/os/image/IDynamicSystemService.aidl
index df0a69b47225..a5a40ad55853 100644
--- a/core/java/android/os/image/IDynamicSystemService.aidl
+++ b/core/java/android/os/image/IDynamicSystemService.aidl
@@ -125,4 +125,9 @@ interface IDynamicSystemService
      *                      valid VBMeta block to retrieve the AVB key from.
      */
     boolean getAvbPublicKey(out AvbPublicKey dst);
+
+    /**
+     * Returns the suggested scratch partition size for overlayFS.
+     */
+    long suggestScratchSize();
 }