Parsing test boards from text files to be able to add more and bigger tests

It also adds an assets folder inside of Launcher3 tests.

It also fixes a bug in fullReorder.

Test: atest ReorderWidgets
Flag: none
Bug: 229292911
Change-Id: I7dadd42a3057d353326691163bb7db71a2e9dcc4
diff --git a/tests/Android.bp b/tests/Android.bp
index 81853d1..f9d6f04 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -69,6 +69,7 @@
 android_library {
     name: "Launcher3TestLib",
     srcs: [ ],
+    asset_dirs: ["assets"],
     resource_dirs: ["res"],
     static_libs: [
         "launcher-aosp-tapl",