gopls: change the default value of "symbolScope" to "all"

Following discussion on golang/go#37236, let's be a bit careful before
changing behavior. For gopls@v0.12.0, we can keep the default of this
setting at "all", and solicit feedback for which default our users
prefer.

Updates golang/go#37236

Change-Id: Ia92382d808983a6ce566c85d06b82afd2375fb90
Reviewed-on: https://go-review.googlesource.com/c/tools/+/494217
TryBot-Result: Gopher Robot <gobot@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/gopls/internal/lsp/source/api_json.go b/gopls/internal/lsp/source/api_json.go
index cfe4c6e..d6fddc9 100644
--- a/gopls/internal/lsp/source/api_json.go
+++ b/gopls/internal/lsp/source/api_json.go
@@ -208,7 +208,7 @@
 						Doc:   "`\"workspace\"` matches symbols in workspace packages only.\n",
 					},
 				},
-				Default:   "\"workspace\"",
+				Default:   "\"all\"",
 				Hierarchy: "ui.navigation",
 			},
 			{