Allowlist apexer for bp2build

This also introduces a workaround for the fact that
apexer depends on aapt2, but aapt2 doesn't build
with bp2build yet. Aapt2 is removed from apexer's
requirements during bp2build.

Bug: 204244290
Test: ./build/bazel/ci/bp2build.sh
Change-Id: I837597ce035c7d5c06e1a3957166583a7a94b5c7
diff --git a/bp2build/python_binary_conversion_test.go b/bp2build/python_binary_conversion_test.go
index dfa11d1..22bd028 100644
--- a/bp2build/python_binary_conversion_test.go
+++ b/bp2build/python_binary_conversion_test.go
@@ -43,9 +43,10 @@
     }`,
 		expectedBazelTargets: []string{
 			makeBazelTarget("py_binary", "foo", attrNameToString{
-				"data": `["files/data.txt"]`,
-				"deps": `[":bar"]`,
-				"main": `"a.py"`,
+				"data":    `["files/data.txt"]`,
+				"deps":    `[":bar"]`,
+				"main":    `"a.py"`,
+				"imports": `["."]`,
 				"srcs": `[
         "a.py",
         "b/c.py",
@@ -83,6 +84,7 @@
 		expectedBazelTargets: []string{
 			makeBazelTarget("py_binary", "foo", attrNameToString{
 				"python_version": `"PY2"`,
+				"imports":        `["."]`,
 				"srcs":           `["a.py"]`,
 				"target_compatible_with": `select({
         "//build/bazel/platforms/os:android": ["@platforms//:incompatible"],
@@ -116,7 +118,8 @@
 		expectedBazelTargets: []string{
 			// python_version is PY3 by default.
 			makeBazelTarget("py_binary", "foo", attrNameToString{
-				"srcs": `["a.py"]`,
+				"imports": `["."]`,
+				"srcs":    `["a.py"]`,
 				"target_compatible_with": `select({
         "//build/bazel/platforms/os:android": ["@platforms//:incompatible"],
         "//conditions:default": [],
@@ -148,6 +151,7 @@
 				 }`,
 		expectedBazelTargets: []string{
 			makeBazelTarget("py_binary", "foo-arm", attrNameToString{
+				"imports": `["."]`,
 				"srcs": `select({
         "//build/bazel/platforms/arch:arm": ["arm.py"],
         "//build/bazel/platforms/arch:x86": ["x86.py"],