Fix telemetry to work on reinstantiating new lib cli (#761)

# What does this PR do?

Since we maintain global state in our telemetry pipeline,
reinstantiating lib cli will cause us to add duplicate span processors
causing sqlite to lock out because of constraint violations since we now
have two span processor writing to sqlite. This PR changes the telemetry
adapter for otel to only instantiate the provider once and add the span
processsors only once.

Also fixes an issue llama stack build


## Test Plan

tested with notebook at
https://colab.research.google.com/drive/1ck7hXQxRl6UvT-ijNRZ-gMZxH1G3cN2d#scrollTo=9496f75c

llama_stack/cli/stack/build.py

@@ -4,9 +4,7 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 import argparse
-
 import importlib.resources
-
 import os
 import shutil
 from functools import lru_cache
@@ -14,14 +12,12 @@ from pathlib import Path
 from typing import List, Optional
 
 from llama_stack.cli.subcommand import Subcommand
-
 from llama_stack.distribution.datatypes import (
     BuildConfig,
     DistributionSpec,
     Provider,
     StackRunConfig,
 )
-
 from llama_stack.distribution.distribution import get_provider_registry
 from llama_stack.distribution.resolver import InvalidProviderError
 from llama_stack.distribution.utils.dynamic import instantiate_class_type
@@ -296,6 +292,7 @@ class StackBuild(Subcommand):
                 / f"templates/{template_name}/run.yaml"
             )
             with importlib.resources.as_file(template_path) as path:
+                run_config_file = build_dir / f"{build_config.name}-run.yaml"
                 shutil.copy(path, run_config_file)
             # Find all ${env.VARIABLE} patterns
             cprint("Build Successful!", color="green")