Break up app.go.

Test: m nothing + TreeHugger
Change-Id: I64c6d7f10530c424bc282d8111dfaf9159426f00

java/Android.bp

@@ -22,6 +22,8 @@ bootstrap_go_package {
         "androidmk.go",
         "app_builder.go",
         "app.go",
+        "app_import.go",
+        "app_set.go",
         "boot_jars.go",
         "builder.go",
         "device_host_converter.go",
@@ -46,6 +48,7 @@ bootstrap_go_package {
         "prebuilt_apis.go",
         "proto.go",
         "robolectric.go",
+        "rro.go",
         "sdk.go",
         "sdk_library.go",
         "sdk_library_external.go",
@@ -57,6 +60,8 @@ bootstrap_go_package {
     ],
     testSrcs: [
         "androidmk_test.go",
+        "app_import_test.go",
+        "app_set_test.go",
         "app_test.go",
         "device_host_converter_test.go",
         "dexpreopt_test.go",
@@ -66,6 +71,7 @@ bootstrap_go_package {
         "jdeps_test.go",
         "kotlin_test.go",
         "plugin_test.go",
+        "rro_test.go",
         "sdk_test.go",
     ],
     pluginFor: ["soong_build"],