Add a few missing package-info.java (#1776)

* Add a few missing package-info.java

* Spotless

api/src/main/java/io/opentelemetry/baggage/spi/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** The SPI (service provider interface) for initializing the OpenTelemetry baggage API. */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.baggage.spi;
+
+import javax.annotation.ParametersAreNonnullByDefault;

api/src/main/java/io/opentelemetry/metrics/spi/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** The SPI (service provider interface) for initializing the OpenTelemetry metrics API. */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.metrics.spi;
+
+import javax.annotation.ParametersAreNonnullByDefault;

api/src/main/java/io/opentelemetry/trace/attributes/package-info.java

@@ -0,0 +1,14 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * OpenTelemetry semantic attributes.
+ *
+ * @see io.opentelemetry.trace.attributes.SemanticAttributes
+ */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.trace.attributes;
+
+import javax.annotation.ParametersAreNonnullByDefault;

api/src/main/java/io/opentelemetry/trace/propagation/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** Default OpenTelemetry remote context propagators. */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.trace.propagation;
+
+import javax.annotation.ParametersAreNonnullByDefault;

api/src/main/java/io/opentelemetry/trace/spi/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** The SPI (service provider interface) for initializing the OpenTelemetry tracing API. */
+@ParametersAreNonnullByDefault
+package io.opentelemetry.trace.spi;
+
+import javax.annotation.ParametersAreNonnullByDefault;