Stop using `group_static_libs` property

This property is now ignored, so there is no need to set it.
For more details, see the bug and/or "Effecient archive file handling"
in https://lld.llvm.org/NewLLD.html#key-concepts

Bug: 189475744
Test: Manual build succeeds
Change-Id: I9522372d0b9f570448101536e93a269295708d2f
diff --git a/build/hidl_interface.go b/build/hidl_interface.go
index 6850055..101b20b 100644
--- a/build/hidl_interface.go
+++ b/build/hidl_interface.go
@@ -820,7 +820,6 @@
 			"libhidladapter",
 		}, wrap("", dependencies, "-adapter-helper"), cppDependencies, libraryIfExists),
 		Export_generated_headers: []string{name.adapterHelperHeadersName()},
-		Group_static_libs:        proptools.BoolPtr(true),
 	})
 	mctx.CreateModule(hidlGenFactory, &nameProperties{
 		Name: proptools.StringPtr(name.adapterSourcesName()),
@@ -846,7 +845,6 @@
 			"libhidladapter",
 			name.adapterHelperName(),
 		}, wrap("", dependencies, "-adapter-helper"), cppDependencies, libraryIfExists),
-		Group_static_libs: proptools.BoolPtr(true),
 	})
 
 	if shouldGenerateVts {
diff --git a/build/properties.go b/build/properties.go
index c88bbef..b0c90ee 100644
--- a/build/properties.go
+++ b/build/properties.go
@@ -35,7 +35,6 @@
 	Recovery_available        *bool
 	Generated_sources         []string
 	Generated_headers         []string
-	Group_static_libs         *bool
 	Shared_libs               []string
 	Static_libs               []string
 	Export_shared_lib_headers []string