Fix build script: set output path explicitly

dev_sign_bundle uses `out/dist` as default out directory. It should
respect DIST_DIR setting.

Bug: 281617982
Test: git_mainline-widevine-release/mainline_modules-user
Change-Id: I2ede21b099b512c948e4e83702a1478982acc779

libwvdrmengine/apex/device/build.sh

@@ -97,7 +97,8 @@ function build_bundles() {
 # inputs: ${DIST_DIR}/${apex}.aab
 # outputs: ${DIST_DIR}/dev_keys_signed/${apex}/${apex}.apks
 function sign_bundles() {
-  ${DEV_SIGN_BUNDLE} --input_dir "${DIST_DIR}"
+  ${DEV_SIGN_BUNDLE} --input_dir "${DIST_DIR}" \
+    --output_dir "${DIST_DIR}/dev_keys_signed"
 }