Make external workspace handling forwards and backwards compatible.

Add a field to the IntelliJ aspect proto which handles both current and future
formats.

--
PiperOrigin-RevId: 149559228
MOS_MIGRATED_REVID=149559228

src/main/protobuf/intellij_ide_info.proto

diff --git a/src/main/protobuf/intellij_ide_info.proto b/src/main/protobuf/intellij_ide_info.proto
index a207590..730b0bf 100644
--- a/src/main/protobuf/intellij_ide_info.proto
+++ b/src/main/protobuf/intellij_ide_info.proto
@@ -23,10 +23,16 @@
   string relative_path = 2;
   bool is_source = 3;
 
-  // set for derived artifacts (is_source = false)
+  // path from the execution root to the actual root:
+  // exec_root + root_execution_path_fragment + relative_path = absolute_path
   string root_execution_path_fragment = 4;
   // whether this artifact comes from an external repository (bazel only)
   bool is_external = 5;
+
+  // The contents of relative_path and root_execution_path_fragment have changed
+  // for external workspaces. This is a temporary field to distinguish between
+  // the two versions.
+  bool is_new_external_version = 6;
 }
 
 message LibraryArtifact {

src/main/protobuf/package_manifest.proto

diff --git a/src/main/protobuf/package_manifest.proto b/src/main/protobuf/package_manifest.proto
index 0c9c40d..d5106a2 100644
--- a/src/main/protobuf/package_manifest.proto
+++ b/src/main/protobuf/package_manifest.proto
@@ -25,10 +25,16 @@
   string relative_path = 2;
   bool is_source = 3;
 
-  // set for derived artifacts (is_source = false)
+  // path from the execution root to the actual root:
+  // exec_root + root_execution_path_fragment + relative_path = absolute_path
   string root_execution_path_fragment = 4;
   // whether this artifact comes from an external repository (bazel only)
   bool is_external = 5;
+
+  // The contents of relative_path and root_execution_path_fragment have changed
+  // for external workspaces. This is a temporary field to distinguish between
+  // the two versions.
+  bool is_new_external_version = 6;
 }
 
 message JavaSourcePackage {